THE PROBLEMS OF THE INFINITE AND THE CONTENUUM IN SOME MAJOR PHILOSOPHICAL SYSTEMS or THE ENLIGHTENMENT Thesis for ”To Dogma of DH. D. MICHIGAN STATE UNIVERSITY Rolf A. George 1961 {mass This is to certify that the thesis entitled "The Problems of the Infinite and the Continuum in Some Major Philosophical Systems of the Enlightenment" presented by Rolf A. George has been accepted towards fulfillment of the requirements for Ph.D. in Philosophy degree William J. Callaghan Major professor DueFebruary 22, 1961 0-169 LIBRARY Michigan State ‘1 University I”- w'wW—“l ABSTRACT THE PROBLEMS OF THE INFINITE AND THE CONTINUUM IN SOME MAJOR PHILOSOPHICAL SYSTEMS OF THE ENLIGHTENMENT by Rolf A. George The philosophers discussed in this dissertation are Leibniz, Berkeley, Bayle, Kant, and Bolzano. Its aim is to show that certain difficulties connected with infinite and continuous sets were recognized by these philosophers, and that their systems were, at least in part,designed in such a way that these difficulties did not arise in them. Notably the so—called Paradox of Galileo played a major role in this respect: Galileo had shown that a one-to-one correspondence can be established between integers and their squares, and Leibniz realized that it is a property of all infinite sets that they have subsets the members of which can be brought in such a biunivocal correspondence with the members of the original set. Up to Bolzano, this was held to contradict the "wholly reliable" Euclidean axiom that the whole is bigger than its part, and was used to prove that infinite sets are impossible. Berkeley, for one, was aware of precisely this problem when he developed a metaphysic in which infinite sets do not occur. Rolf A. George Leibniz' solution consisted in the following: He assumed that the number of monads constituting or "giving rise" to any given finite body is always larger than any finite number, but that it is not permissible to speak of these monads as forming a set.‘ When we nevertheless speak of a given body as forming Qgg.thing, we are taking a liberty that is excusable in everyday discourse. only‘ for reasons of its pragmatic efficacy. Such statements cannot be tolerated in a language that endeavors an ultimately reliable descrip- tion of the universe. For, if a given body were an infinite set of parts, then it would have contradictory properties, so Leibniz believed. Kant asserted that a phenomenal Object does not have an infinite number of parts already in it. Its being extended is the result of the form of outer sense. ‘Hence it cannot be said that it has more parts than this sense distinguishes in it. However, an operative decomposition of such an object can be carried out, and a rule of reason guarantees that this decomposition has no final Stage. But this is not the same as to say that the object is a set of infinitely many members, or a whole with infinitely many parts, and this distinction supposedly forestalls the arising of paradox.“ Bolzano was the first to realize that the so-called Rolf A. George Paradox of Galileo is no paradox at all, but simply describes a common property of all infinite sets. As concerns the constitution of continua the problem was that neither the assumption that a continuum ultimately consists of unextended parts, nor that it consists of extended parts seemed defensible. Against the former case it was argued that unextended parts, no matter how many, cannot make a finite extension, against the’latter that extended parts are not ultimate, but are further diviSiblei ‘Bayle'held that none of the logical alternatives are defensible, so that no one need bother to change whatever opinion he happens to have on the subject. Berkeley argued that there is no extension in objects, but only extension as perceived, and a phenomenal object cannot be said to have parts smaller than a minimum sensibile. Hence, any continuous shape will consist of a finite number of smallest particles, and the difficulty disappears. BerkEIey_ held this to be one of the most important conséquences of the "immaterial hypothesis". Kant's solution has already been sketched in connection with the Paradox of Galileo. Leibniz' position was that there is no aetualcontinuum, but that any continuum is an "intellectUal cbnstrhct”.i It must be analyzed as a concept, iue. into simpler concepts, not' into smaller parts. A part of a given continuous entity is Rolf A. George considered to be a more complicated construct than the whole of which it is a part, since it must be described by refer- ence to that whole. Thus continua are said to be ”prior” to their parts. Leibniz consequently held that the quest for the ultimate spatial parts of continua is pointless. Bolzano declared that in a continuum every point has a neighbor within any distance, no matter how small. This definition, although ultimately unsatisfactory, proved to be of great help in discovering various important properties of continuous sets. The purpose of this dissertation is not to sketch the evolution of thought on the subjects of infinite and continuous sets, but to show how the problems connected with them were no less important in the development of Enlightenment philosophy than the epistemological predicaments customarily discussed in histories of philosophy. THE PROBLEMS OF THE INFINITE AND THE CONTINUUM IN SOME MAJOR PHILOSOPHICAL SYSTEMS OF THE ENLIGHTENMENT by '0 \ {o Rolf A5 George A THESIS Submitted to Michigan State University in partial fulfillment of the requirements ' for the degree of DOCTOR OF PHILOSOPHY .Department of Philosophy I961 I 7 ./_" /"" o... d .p‘ éfl/gd To Hellmut Keusen ACKNOWLEDGEMENT I should like to express my gratitude and appreciation to Professors Rudner, Callaghan and Zerby for all the help and encouragement they have extended to me during the course of this investigation. CONTENTS Introduction. Chapter I: Leibniz. Chapter II: Berkeley. Chapter III: Bayle. Chapter IV: Kant. Chapter V: Bolzano. Conclusion. .19 .63 111 133 192 211 INTRODUCTION In 1662 Arnauld wrote the following about the pro- blems of the infinite in his Port Royal Logic.l The most compendious way to the full extent of knowledge is not to toil ourselves in the search of that which is above us, and which we can never rationally expect to com- prehend. Such are those questions that relate to the Omnipotency of God, which it would be ridiculous to confine within the narrow limits of our Understandings; and generally, as to whatever partakes of Infinity, and lies over- whelmed under the multitude of thoughts, con- tradicting one another. Hence may be drawn the most convenient and shortest solution of many questions, about which there will be no end of disputing, so long as Men are infected with the Itch of dispute, in regard they can never be able to arrive at any certain knowledge, whereby to assure and fix the Understanding. Is it possible for God to make a Body infinite in quantity, a movement infinite in swiftness, a multitude infinite in number? Is a number infinite even or odd? Is one infinite more extensive than another? He that should answer once for all, I know nothing of it, may be said to have made as fair a Progress in a moment, as he that had _¥ l(Antoine Arnauld) Logic or the Art of Thinking, Part 4, Ch. 1. (The quotation is taken from the 2nd edition of the English translation, London 1693, p. 390 F.) been beating his Brains twenty years, about these Niceties. The only difference between these Persons is, that he that drudges day and night about these Questions, is in the greatest danger of falling a degree lower than bare Ignorance; which is, to believe he knows that which he knows not at all. Contrary to the spirit of this quotation. Arnauld then proceeds to give various demonstrations for the infinite divisibility of matter, which, following Descartes. he considers to be continuous. Before Arnauld. Descartes had similarly proclaimed that there is not much point to an investigation of the infinite division of matter, since it must be considered to transcend our finite understanding,2 and much the same reasons were advanced by Galileo when he cautioned "let us remember that we are dealing with infinites and indi- visibles, both of which transcend our finite understanding. the former on account of their magnitude. the latter . 3 because of their smallness." These quotations express a sentiment apparently quite widespread around the middle of the seventeenth 2Descartes. Les Principes de la Philosophie, Part II. No. 35, Oeuvres. Ed.Victor Cousin, Paris 1824, vol. 3. p. 150. 3Galileo Galilei, Dialogues Concerning Two New Sciences, Ed. Henry Crew and Alfonso de Salvio, New York. 1914, p. 26. century: a general resignation before the problems of infinite sets and the logic of the continuum. But this attitude changed very rapidly: a mere half century after the Port Royal Logic, Collier remarks scornfully about the passages in that work which pertain to our subject that it is indeed a sign "that our understandings are very weak and shallow, when such stuff as this shall not only pass for common sense, but even look like argument."4 At the beginning of the eighteenth century, the appeal to the finitude of our understanding in discussing the apparently incomprehensible properties of infinite sets was no longer considered a philosophically tenable position. A vigorous attack upon these problems had been initiated by Leibniz, _ Bayle, Berkeley, Collier and others, and the belief that the difficulties of the continuum and the infinite must be capable of a rational solution, once gained, was never relinquished until such a solution finally was accomplished around the middle of the last century. The present study is devoted to a discussion of some attempts on the part of various philosophers to find a solution to the problems of continuity and the infinite. 4Arthur Collier, Clavis Universalis, Ed. Ethel Bowman, Chicago, 1909, p. 74. 4 In particular, Leibniz, Bayle, Berkeley, Collier, Kant and Bolzano will be discussed. I wish to establish the thesis that the philosophical systems developed by these philoso- phers had as one of their primary objectives the resolution of the indicated problems; and that this concern can, accordingly, be said to be largely responsible for the particular character which those philosophical systems took on. While we have many historical accounts of mathema- ticians dealing with these and kindred problems, especially problems in analysis, hardly any investigations have been made into the role and importance of the problems of the infinite and the continuum for the nature and structure of metaphysical and epistemological systems in the seventeenth and eighteenth century. This is all the more surprising as the philosophical literature of that age contains so many references to these difficulties, so many proposals for their resolution that the sheer frequency of these remarks would suffice to legitimate them as among the persistent problems of philosophy in those centuries. A further fact which should have drawn the attention of historians to these philosophical labors is that the mathematicians of the seventeenth and eighteenth century tended to regard the problems of the continuum as "pre-mathematical": they were to be resolved through metaphysical speculation, much in the same way in which Plato wanted to establish the truth of the axioms of geometry through dialectics. This sentiment is described by Boyer in his Concepts of the Calculus: The attitude of most of the mathematicians of the seventeenth century...was that of doubt. They employed infinitesimals and the infinite on the assumption that they existed. and treated the continuous as though made up of indivisibles, the results being justified pragmatically by their consistency with Euclidean geometry. In any case the attitude was not that of unpre- judiced postulation and definition. followed by logical deduction .5 One might add that the situation did not appreciably change during the eighteenth century. and only in the nineteenth, commencing with Bolzano. were the fundamental problems of analysis. of the continuum and of infinity attacked in a new spirit within the field of mathematics itself. Before that time, problems in the foundation of mathematics were relegated to the metaphysician. But it was not only the case that the mathematicians were hesitant to attack the foundation—problems of their science. and let their results justify their assumptions; the philosophers of the age felt 5Carl B. Boyer. The Concepts of the Calculus,(New York), 1949. p. 305. 6 it incumbent upon themselves to supply what the mathemati- cians avoided. Kant speaks of having to bring about a reconciliation of geometry and metaphysics; Berkeley urges the mathematicians to join metaphysics to their mathematics; and Leibniz admonished the geometricians to leave well alone the problems of the continuum:"...the geometer does not need to encumber his mind with the famous puzzle of the composition of the continuum..."6 In a sense. the philosophy of mathematics was not only thought to have to describe mathematics, but also to have to establish its first principles. Of course. the notion that the latter should be the task of philosophy could arise only if the former was not properly performed In a way. all the philosophical investigations that were undertaken in this direction stem from misconceptions con- cerning the nature of mathematics. The nature of these misconceptions. their genesis and consequences embodied in 6cf. George Berkeley. Of Infinites. The Works of George Berkeley. ed. A. A. Luce and T. E. Jessup. London 1948 ff., Vol. 4. pp. 235-238. p. 238. In the sequel, Berkeley will be quoted after this edition. which will be referred to simply as The Works of George Berkeley. G. W. Leibniz. Discourse on Metaphysics. section X. in Leibniz, Selections ed Philip P. Wiener, New York 1951. (In the sequel quoted as Wiener). p. 303. these philosophical labors constitute the subject of the presentidiscussion. The methods of approaching the problems of the con— tinuum were. for example. strongly influenced by the assump- tion that geometry is the science whose task it is to describe empirical space or phenomenal space. This had led some of the philosophers under discussion to regard the problem of the composition of the continuum as synonymous with the problem of the composition of visually continuous surfaces or lines. In others we find the problems of the continuum discussed in connection with the compositiOn of matter or of space or of time. Thus our problem was dis- cussed under various guises and one must not expect to find questions of mathematics divorced from considerations of physics or from discussions concerning the structure of our experience. After all. the enquiries concerning the nature of the continuum are found embedded in larger treatises. and it is characteristic of all these approaches that they claim to make the puzzlements of the continuum disappear if only the problem is seen in the right (empiricist or ideal- ist or what not) context. It is customary. in the introductory chapter of an investigation such as the present one. to state precisely the nature of the problem to be discussed in it. So far I have offered not much more than vague generalities. Evidently. in order to become more explicit I ought to offer a definition of such key terms as "continuum" and "infinite" if I wish to make the extent and concern of the present dissertation perfectly clear. In trying to do so. however. a perplexing difficulty presents itself: It has often been claimed, especially by mathematicians, that the first rigorous definition of "continuous" was given by Dedekind. and that before this momentous event the word "continuous" was associated with a more or less vague notion of hang-togetherness.7 If this were so. then we would. strictly speaking. have no assurances that the philosophers we are about to investigate were in fact all dealing with the same problem (as was. say. Dedekind) when they spoke of the problem of the continuum. But the difficulty is not as severe as it might seem. While no precise definition of continuity was available. there was always the example of the geometrical line. the points on which were always con— sidered to form a continuous set. Thus the problem was not simply to find a precise definition of a hitherto vague term, ‘7Cf. Boyer. op. cit, pp. 42. 291. 9 but to describe accurately the arrangement or order of the points in a line in such a way that, for example, the axioms of Euclid could be fulfilled. If it had been otherwise, then there could be no reason why the definitions advanced by Leibniz and later by Mach, namely that a line is con— tinuous if between any two points on that line there lies another point, should have to be rejected.8. We could simply treat this definition as a hortatory one and assume that it renders precise a concept that had so far been vague. But the point is that linear point sets can be produced which fulfill Leibniz' requirement but which do not allow a development of geometry in Euclid‘s sense. For example, conditions can be described in which "a straight line meets two straight lines, so as to make the interior 8Leibniz defines "continuity" thusly: "There is con- tinuOus extension whenever points are assumed to be so situated that there are no two between which there is not an intermediate point." (Bertrand Russell, A Critical Exposition of the Philosophy of Leibniz, 2nd ed., London, 1937, p. 247). For Mach cf. Boyer, op. cit., p. 291: "The scientist Ernst Mach likewise regarded this property of denseness of an assemblage as constituting its continuity." (Die Principien der Warmelehre, historisch-kritisch entwickelt 2nd. ed. Leipzig, 1900, p. 71. Similar considera- tions apply to Bolzano's definition of 'continuity'. Bolzano claims that a point set is continuous if, and only if, the points are situated in such a way that "every single one of these points has at least one neighbor in the set within any distance, no matter how small. (Bernard Bolzano, ggpgr doxien des Unendlichen ed. Fritz Prihonsky, Hamburg 1955, (lst. ed. Leipzig 1851), p. 73). 10 angles on the same side of it taken together less than two right angles" where nevertheless the two straight lines do not "at length meet" because one of them runs through a gap in the other. i.e they do not have a point in common. The defhfltions advanced by Leibniz. Bolzano and Mach was at length discarded because they did not imply all the properties associated with the preanalytic notion of con- tinuity. But this only goes to show that this preanalytic notion was a fairly precise one. What was lacking was a definition of "continuous" in terms of the components of the continuum, or. as the philosophers of the age were wont to put it. the problem of the composition of the continuum was unresolved, However. the mere fact that the term was always applied to the same kinds of object assures us that different philosophers. when speaking about the continuum, were really dealing with the same problem. I have come to this conclusion in spite of the fact that the descriptions of the composition of the continuum vary from wildly meta— phorical. as in the case of Galileo, to dryly sober in the case of Bolzano. Galileo writes in the Dialogues Concerning 9Cf. Euclid's Elements. ed. Isaac Todhunter. London 1955. Axiom 12. 11 Two New Sciences. Having broken up a solid into many parts. having reduced it to the finest of powder and having resolved it into its infinitely small ‘ indivisible atoms, why may we not say that this solid has been reduced to a single continuum. perhaps a fluid like water or mercury or even a liquified metal?lO It must be noted that the fact that Galileo was unable to give an adequate description of the composition of the continuum did not prevent him from employing the term correctly, as his geometrical researches amply testify. It is this similarity in use that assures us that Galileo meant to deal with the same problems as later Bolzano and Cantor. The situation is slightly more difficult in the case of the concept of infinity. Apparently the concept of infinity has always been surrounded with certain romantic notions. It is still customary to speak about somebody's "infinite compassion." Infinity seems to have always been considered by some people as an honorific attribute: Descartes speaks of God's infinite and man's finite mind, and similar examples could be adduced in great abundance. loGalileo, o . cit., p. 39f. 12 Fortunately. the sense in which the term "infinity” is used is usually made clear by the context. But let me give an example of the confusion that this ambiguity of the term frequently caused: Collier. in his Clavis Unfive:salis attempts to show, as Berkeley did before him, that there is no external matter. After having done this to his satisfaction. he tries to show that certain contradictions follow from the contrary assumption, namely that there is external matter. He writes: "External matter. as a creature. is evidently finite. and yet as external is evidently infinite. in the f number of its parts. or divisibility of its substance. "11 From this he concludes that a contradiction follows from the assumption that there is external matter. namely, such matter would have to be both finite and infinite ' But this contradiction is only apparent. since the word 'finite' is construed as the negation of an honorific attribute that Tlas nothing to do with the mathematical notion of infinity. Collier puts it thus:12 llArthur Collier, Clavis Universalis, ed. Ethel Bowman. Chicago 1909. p. 69. 121bid., 02. cit., p. 68. 13 "Infinite is to be absolute. finite. to be not absolute." Now since God is the only absolute being. infinity can properly be attributed only to Him and not to anything that depends for its being upon God‘s concurrence. In this sense external matter is said to be finite because it is a crea- ture. Now the term 'infinite' in the first quotation above evidently denotes the number of members in a set and thus can clearly not be construed as the contradictory of the term "finite“ in the same quotation. as Collier would have it. This example demonstrates amply the confusion caused by the ambiguity of 'infinite'.13 13We have seen that it was frequently argued at the time that man cannot understand the composition of the continuum because his mind is finite. but that only God. whose mind is infinite can have an adequate understanding of it. Commentators have often argued that 'finite' and 'infinite' are here used in a non-quantitative way. They speak of the "qualitative" infinite. Hegel even attaches a Value—discrimination to this distinction when he condemns ‘the quantitative infinite as "das schlechte Unendliche". iln.the text I have argued that the two conceptions should the kept distinct, but it might be well to point out that tlaere is a pretty obvious connection between these two con— CHepts, especially among the Cartesians. I believe that (tqualitative) infinity was thought to be that attribute of tine understanding of God which allowed him to comprehend .tJae nature of infinite sets. in particular the composition .<>f the continuum. The postulation of this particular attri-' ibute of God's understanding would preserve. after a fashion. the rationality of the world. for if not even God could reconcile the apparently contradictory properties of infin- ite sets. then we must think of ourselves as somehow surrounded by inconsistent facts. In addition, 'infinite' 14 For obvious reasons I have therefore made it a policy to discuss only such occurrences of 'infinite' as seem to refer to the number of elements in a set. For this reason I have decided not to include a discussion of Spinoza. Spinoza. as far as I can discern. defines "finite after its kind" as a quantity that can always be increased. He says "A thing is called finite after its kind. when it can be limited by another thing of the same nature; for instance a body is called finite because we always conceive another. greater body.".14 A body is finite. then. if something can be added to it. and it would seem that a body is infinite if nothing can be added to it. Or. as Bolzano puts it. Spinoza believed "only that to be infinite which is not capable of further increase, or to which nothing can be added."15 Bolzano points out that many other philosophers and Vvas of course also used as an honorific term. However. the Irelation between the ”qualitative" and the "quantitative" linfinite in 17th century philosophy would bear some further :anestigation- l4 . . . . . . . Benedict Spinoza. Ethics, Definition 21; in: Tp§_ Slgef Works of Benedict de Spinoza. ed. R. H. M. Elwes. ‘N. Y.. 1951. 15Bernard Bolzano, o . cit., § 12, No. 2. 15 mathematicians adhered to this definition of 'infinite'. In the present paper I shall make no attempt to account for any theories of this sort, i.e.. I shall iestrict myself to only such accounts as do not regard an infinite number as the greatest thinkable number. or give similar definitions. As we shall presently see. writers who did not treat infinity as an honorific attribute and who did not adhere to a definition similar to that of Spinoza were able to indicate. quite some time ago, several important properties of infinite sets. One difficulty seems to permeate all the discussions of the continuum that we are about to study9and'that is the sense of 'compose' in the question "of what is the con- tinuum composed?" and we may just as well give it some thought at this juncture. Apparently the continuum was _thought to be "composed" of something in the sense in which a brick wall is composed of bricks. The bricks are the parts of which the brick wall is composed. but there are no components that make up a continuum in this way. Certainly. if we consider a continuous line. the points in this line do not "compose" the line in this sense. We know that if we have more bricks, then we can make a bigger wall, but a larger number of points does not make a longer line than a 16 smaller number of points. Likewise. in a inck wall. a brick has immediate neighbors (provided there is more than one brick in the wall). This does not hold for the points in a line. That the continuum would exhibit such features was a fact not generally reckoned with. and the confusion surrounding this concept can in a large part be explained by assuming that what was sought after were parts of the continuum that would compose it like bricks compose a wall. The abandonment of this preconception was one of the most important conditions. but evidently also one of the condi- tions most difficult to attain before an adequate descrip- tion of the continuum could be given. At this place a few remarks are also in order con- cerning the method of the subsequent enquiries. Our task is the exposition. at least in part. of certain philosophi— cal systems. Eor these expositions I have adopted the following strategies: I attempt to identify the problems which these systems Were designed to resolve, and try to delineate the way in which this-resolution took place in each case. At the danger of repeating myself needlessly. I wish to emphasize again that the problems of the infinite and the composition of the continuum hold a place of great eminence among the problems to be reSolved in the systems 17 which will be discussed. This procedure of identifying the initial problems of philosophical systems seems to have certain advantages over other modes of exposition. It makes clear. for one thing. that the philosophy of the enlighten— ment must not be thought of as so much idle speculation: it was to a great extent just as serious an endeavor to resolve the problems indicated as were the later and more successful investigations of mathematicians. Anothe. advantage of this mode of exposition would seem to lie in the following: if it can be shown that, for example. Leibniz adopted the divi- sion between intelligible and phenomenal world with the explicit purpose of resolving certain logical difficulties. then the affirmation of this bifurcation among later ideal- ists, who can think of no problem to be resolved thereby. is just purposeless. ludicrous speculation. a senseless repetition of a philosophical distinction the import of which had been entirely lost. It is a disgrace for the historians of philosophy that the term 'idealist‘ should be applied indifferently to both Leibniz and those who aped him. But a distinction between the two can obviously only be found if one is aware of the problem which precipitated‘the development of ‘ ‘1- Leibniz' system, and the sad lack of such problems, for 18 example. with Fichte. The much touted "historical method" would never be capable of finding this distinction, con- centrating as it does on the lines of development of philosophical ideas. LetthEisuffice as an introduction. I shall take the liberty to make further remarks concerning the mode of my exposition in the body of this dissertation. CHAPTER I LEIBNIZ In discussing the philosophy of Leibniz. formidable difficulties present themselves. Leibniz did not leave a definitive treatment of his philosophy. and his incidental expositions are almost always adapted to the capacity of his correspondent or his immediate audience. or are the ~outgrowth of polemics over certain restricted points. In view of these facts it is necessary for the commentator to adopt a strategy which will organize the material for him and allow him to weave it into a coherent whole. In keep- ing with a general practice, a historical approach to Leibniz is most frequently chosen and the "development" of his philosophy is discussed. ‘Various influences upon him are cited and characteristic alterations of delivered opinions are noted. Under this viewpoint. Leibniz appears as a great synthesizer of previously held philosophical opinions. Latta, for example,notes correctly that "the philosophical work of Leibniz was an endeavor to reconcile the notion of substance as continuous with the contrary notion of substance as consisting of indivisible 20 elements".16 But while he recognizes the importance of the subject to Leibniz. he thinks of him as primarily interes- ted in affecting a synthesis of two positions that were in fact held by his predecessors. namely Descartes on one hand and the atomists on the other. A much more blunt statement of the view that Leibniz was. in the main, a synthesizer of previously held philosophical views is. found in Maziarz' Philosophy of Mathematics. Maziarz writes: "His (Leibniz') countless references to ancient, medieval. and contemporary thinkers...reveal his basic trend and tendency: to compromise and synthesize. to remove individual differences. to harmonize speculative opposition in his own center of perspective "17 The viewpoint here characterized can easily be substantiated through quota- tions from Leibniz himself. Thus in the Nouvaux Essais. Leibniz writes: "This system appears to unite Plato and Democritus, Aristotle and Descartes. the Scholastics with the Moderns, theology and ethics with reason. It seems to 16Robert Latta, Introduction to: Leibniz. The Monadology. ed. R. Latta. lst edition. Oxford 1898, p. 28. 17Edward A. Maziarz. The Philosophy of Mathematics, New York, 1950, p 58. - 21 take the best from all sides..."18 It must be noted that for a critical exposition of Leibniz it is really of secondary importance to discover the historical sources of various parts of Leibniz philosophy and to discuss the psychological motivation for the development of his system. It must be noted. and will be substantiated in the sequel. that the views which Leibniz synthesized were each of them held irrefutable by Leibniz without much regard for their historical origin. Thus it is of primary importance to undertake a reconstruction of his system. and it is only of secondary philosophical interest to trace historical ori- gins and psychological motivations. I believe that in thus reconstructing Leibniz' system better justice is done to the spirit of Enlightenment philosophy, which took its metaphysical problems just as seriously as we take problems of mathematics or methodology. and which was not given to the transaction of speculations out of piety for received opinions. Thus. in this chapter I do not wish to advance a psychological or historical thesis concerning the genesis of Leibniz' philosophy. ‘Rather. I wish to point out that he was aware of certain problems connected with the con- lBLeibniz. New Essays Concerning Human Understanding, ed. Alfred Go Langley, La Salle, 1949, p. 66 (Book 1. Ch. 1). 22 tinuum. and that his philosophical system can be envisaged as being designed. to a large extent, in order to resolve these problems. Thus I shall not argue that the problems of the continuum were the psychological starting point of his speculations. On the other hand. the present chapter can be taken as an attempt to show that there are no inner- systematic reasons against this assumption. However. the establishment of the psychological thesis itself would require a good deal of additional detective work which I do not consider to be the responsibility of the philosophi- cal commentator. A different strategy for the exposition of Leibniz' system has been chosen by Bertrand Russell. Properly, Russell does not pay much attention to the historical ori- gin of Leibniz' views. but treats his philosophy, at least. in its speculative parts, as a coherent system and claims that he attempts to develop it from a small set of premises: These premises are: I Every proposition has a subject and a predicate, II. A subject may have predicates which are qualities existing at various times (such a subject is called a substance). III. True propositions not asserting existence at particular times are necessary and analytic. but such as assert existence at particular times are contingent and synthetic. The latter depend upon final causes. IV The ego is a 23 substance. V. Perception yields knowledge of an external world, i e., of existents other than myself and my states.19 One might expect that Russell would develop Leibniz' system from these premises with the aid of the laws of logic. But he does not give us the treat of demonstrating Leibniz' philosophy as an axiomatic system, and one might excuse his self-deception on this count by pointing out that his book on Leibniz preceded his logical work. He claims, how- ever. that "the first four of the above premises...1ead to the whole or nearly the whole of the necessary propositions of the system."20 I believe that a reconstruction of Leibniz' philoso— phy as an axiomatic system would not present to us the spectacle of a large number of theorems following from a half dozen or so axioms. as one might expect from the philosophical system of a man with Leibniz' logical acumen. Notice that Russell merely claims to have identified the “principal" premises of the system, although he fails to make clear in what sense he takes certain premises to be more important than others. 19Bertrand Russell. A Critical Exposition of the Philosophyiof Leibniz. 2nd ed., London 1937, p. 4. ZOIbid. 24 In keeping with the general procedures set forth in the introduction I shall attempt to give an exposition of parts of Leibniz' philosophy by a method different from the above indicated two. I believe that Leibniz‘ major problem lay in the fact that he adopted a number of propositions each of which he had to consider as well established, but which together seemed to form an inconsistent set. It seems that through an identification of these propositions a reasonable understanding of the problems of Leibniz‘ sys- tem can be provided. I shall therefore proceed to point out what these propostions were and we shall see that, in order to harmonize them. a large part of Leibniz' system had to be developed. In identifying the propositions in question I shall occasionally refer to the history of their discovery, but I want this taken as incidental information. I do not wish to appear to make the same error that I have criticized in Maziarz. Leibniz knew that the members of an infinite collection can be brought in a one to one correspondence with the members of a proper subset of that collection. This fact was already known to Galileo. who wrote in the Dialogues Concerninngwo New Sciences: 25 Salv. Very well; and you also know that just as the products are called squares. so the factors are called sides or roots; while on the other hand those numbers which do not consist of two equal factors are not squares. Therefore, if I assert that all numbers. including both squares and nOn-squares. are more than the squares alone, I shall speak the truth, shall I not? Simp. Most certainly- Salv. If I should ask further how many squares there are. one might reply truly that there are as many as the corresponding number of roots, since every square has its own root and every root its own square, while no square has more than one root and no root more than one square. Simp. Precisely so, Salv. But if I inquire how many roots there are, it cannot be denied that there are as many as there are numbers, because every number is the root of some square. This being granted we must say that there are as many squares as there are numbers, because they are just as numerous as their roots. and all the numbers are roots. Galileo was quite puzzled with his discovery and he assumes that the difficulty can in part be resolved by assuming that "the attributes 'equal'. ‘greater'. and 'less', are not applicable to infinite, but only to finite. 21Galileo Galilei, Dialogues Concerning Two New §£3§§g§§. Translated and ed. by Henry Crew and Alfonso De Salvio. N. Y., 1914, p. 32. 26 quantities."22 Any difficulty that might remain must be attributed to our finite understanding which cannot entirely cope with the problems of the infinite.23 Leibniz was familiar with this result. He occasion- ally claims to have discovered it himself. Thus he writes: "Many years ago I proved that the number or sum of all, numbers involves a contradiction (the whole would equal the part)."24 In the Nouvaux Essais he writes: "But there is no infinite number. neither line nor other infinite quantity, if these are understood as veritable wholes, as is easy to show."25 Here he obviously alludes to the same result. It is noteworthy that Leibniz realized that the paradox of Galileo not only applies to discrete sets such as the set of natural numbers, for which alone Galileo pre- sents a proof, but that the paradox is seen to apply also to such point sets as lines. which are here considered as 22Ibid 23See Introduction. p. 2. 24Letter to Bernoulli, 1698, Wiener, o . cit., 25Leibniz, Nouvaux Essais, p. 161, (Bk. II, Ch. XVII); 27 just another kind of infinite quantity. The clearest state- ment of the "Paradox of Galileo" is the following: The number of all numbers implies a contra- diction, which I show thus: To any number there is a corresponding number equal to its double Therefore the number of all numbers is not greater than the number of even numbers 6i.e. the whole is not greater than its part. It is perhaps not unfair to Leibniz to state the preposition in question as "If there is an infinite collec- tion, then it has a proper subset which can be brought in a one to one correspondence with it". This proposition is clearly presupposed in the above presented arguments, especially in the last one. But the arguments are of modus tollens form: they deny the consequent, namely that the part ever is as great as the whole. in order to deny the antecedent, namely that there are infinite collections. Thus we have discovered a second proposition which Leibniz considered established beyond all doubt, namely that the whole is greater than its part. This is the ninth 27 of Euclid's axioms. Leibniz frequently acknowledges his unconditional acceptance of this proposition as for example 26Russell, 0 . cit., p. 244. 27Euclid, The Elements, ed. Issac Todhunter. London, 1955, p. 6. 28 in the Nouvaux Essais: "Euclid says that the whole is greater than its part. a statement which is wholly trust— worthy".28 On another occasion, Leibniz attempts to deduce the principle of whole and part from a definition, He writes: "If a part of a quantity is equal to the whole of another quantity, then the first is called the greater, the second the smaller. Whence the whole is greater than the part."29 However. when Leibniz establishes that there would be as many even numbers as integers. he does not make use of the provisions of his definition, for, clearly, the set of integers has a part which is equal in number to the set of even numbers and that is the set of even numbers itself. Hence by the above definition, the set of even numbers must be called smaller than the set of integers. Moreover, when we think of the set of integers as equal with the set of even numbers, then the whole of which the even numbers are a part must be greater than the set of integers. But that whole is the set of integers itself. -Hence, by the above definition, the set of integers is greater than itself, which makes it impossible to consider 28 Leibniz, Nouvaux Essais, p. 471. 29 . Metaphysical Foundations of Mathematics. Wiener, op. cit., p. 205. 29 ”greater than" as irreflexive, a very odd usage indeed The upshot of this discussion is that Leibniz had very pressing reasons to deny the existence of infinite sets. If there are no infinite sets, then the above definition becomes. of course. quite acceptable. since then the princi- ple of whole and part would generally hold. There are numerous other passages in which Leibniz asserts the principle of whole and part. and occasionally he calls it an axiom.3O The two propositions considered so far. namely the paradox of Galileo and the principle of whole and part could be reconciled with one another, but will jointly lead to the consequence that there are no infinite sets: The following, however, seems to assert the existence of infinite sets and thus forced Leibniz to all manner of speculation as to how it could be reconciled with the first mentioned two propositions. It can be put thus: There is external matter and it is infinitely divisi- ble. It has infinitely many parts. Obvious difficulties arise at once. Leibniz had asserted that we cannot make any statements about infinite 30§pecimen Dynamicum. Wiener. op. cit.. p. 130. 30 sets considered as "veritable units" but that we can only speak of infinite sets as what he calls distributive wholes. Thus while we may form a sentence of the form "Every even number has such and such a property", we are not supposed to write "the class of even numbers is such and such". This restriction becomes problematic once the assumption is made that every piece of external matter forms a whole of infinitely many parts. Then a sentence like "this stone is of such and such a nature" violates the rule that prohibits our speaking of infinite sets as veritable wholes. It seems then that the three propositions, namely the paradox of Galileo, the principle of whole and part, and the assertion of the actual infinite subdivision of any given piece of matter form an inconsistent set. This inconsistency is part of what Leibniz calls the "labyrinth of the continuum". Actually, Leibniz does not consider external matter to be continuous, but his denial of the real continuity of matter is alreay part of the solutiOn of the problem, as we shall see in the sequel. The reason why the indicated problem must nevertheless be considered to o . Specimen Dynamicum, Wiener, op. cit., p. 130. 31 belong to the so-called labyrinth of the continuum is that many of Leibniz predecessors subscribed to the notion that matter is continuous and therefore infinitely divisible. Leibniz agrees that matter is so divisible. but his views on the continuity of matter are rather more complex and shall be discussed later. That Leibniz believed in the actual infinite is shown in the following passage and numerous others. I am so much for the actual infinite that instead of admitting that nature abhors its, as is commonly said, I hold that it affects nature everywhere in order to indicate the perfections of its author. So I believe that every part of matter is, I do not say divisible, but actually divided, and consequently the smallest particle should be considered as a world full of an infinity of creatures.31 That there should be external matter at all was apparently not seriously questioned by Leibniz, at least not in his later years. Russell remarks that only in his earlier years did Leibniz regard the existence of matter as a problem, but that later "he so far forgot his earlier unresolved doubts that, when Berkeley's philosophy appeared, ‘Leibniz had no good word for it. 'The man in Irelandg Tue 3lspecimen calculi universalis. Wiener, op. cit., p. 99. ‘ 32 writes,'who impugns the reality of bodies. seems neither to give suitable reasons, nor to explain himself sufficiently. I suspect him to be one of that class of men who wish to be known by their paradoxesu32 The difficulty then is the following: there are everywhere in nature infinite sets. Every piece of matter can be thought of as such an infinite set. But this assump- tion is not compatible with Leibniz' other results, namely that there is a contradiction in the concept of an infinite set. Since the problem here indicated is connected, his- torically, with the assumption that matter is continuous, let us call it the first problem of the continuum. Its resolution, i.e. the reconciliation of the three proposi— tions so far identified requires the generation of a large part of Leibniz' system. and we can therefore think of these propositions as "nuclear" propositions: the system was generated for the most part to make their simultaneous assertion tenable. In saying that the paradox of Galileo, the principle of whole and part, and the assumption of the actual infinv ite were the propositions for the sake of which a large 32 Russell, op. cit., p. 72. 33 part of the system was developed, I do not wish to give the impression that these propositions should be considered as axioms. Rather. they have a relation to the fundamental assumptions of the system similar to that of the better known theorems of arithmetic to their axioms: they are believed first and only subsequently axioms or premises are sought from which they follow. Before I try to show the ways in which Leibniz attempts his resolution. let me point to a second problem connected with the continuum. This second difficulty had already engaged Descartes. It is the following: The' ultimate parts of the continuum, or of matter when viewed as continuous, can be neither points nor extended particles (so it was argued). Not the former because extension cannot be built up. it was believed, out of unextended parts, not the latter. because extended parts or extended atoms are not ultimate but can be further divided.33 Now the number of parts, whatever their nature, must be infin- ite since a finite number of divisions of a continuous quantity will always result in extended parts which can be further divided. Thus all that can be said is that any 33 Cf. Descartes. Principles. Part II. Principle 20. 34 continuous quantity consists of an infinite number of parts of undetermined nature. This is where Descartes rests the issue. He argues that we must not doubt this division. although we cannot comprehend it.34 The reason why Descartes did not want this division to be put in question is. of course. that he wanted Euclidean geometry to be applicable without restriction to extended objects. and this geometry demands, among other things. that any line, no matter how short. must be divisible. Let us call the problem here indicated the second problem of the continuum. I think that what Leibniz calls the "labyrinth of the continuum" consists of the two problems here identified. It will be noted that what I have called "the first pro- blem of the continuum" attaches to all infinite sets. while the second has to do with continuous sets only. We can take Leibniz' word that his philosophy was to a large extent designed to resolve both these problems. In the beginning of the Theodicee he writes: There are two famous labyrinths. in which our reason often goes astray: the one relates to the great question of liberty and necessity. especially in regard of the production and origin of evil; the other consists in the 34 ‘ Cf.. Ibid., Part II. Principle 35. 35 discussion of continuity and the indivisible points which appear to be its elements. and this question involves the consideration of the infinite. The former of these perplexes falmost all the human race, the latter claims the attention of philosophers alone.35 Latta comments about this: Leibniz makes the Theodicee an investigation of the meaning of liberty and necessity, while in others of his writings he offers a solution of the problem which he describes as the special perplexity of the philosophers. Let us now proceed to sketch that part of Leibniz' system which is required for the solution of the problems of the continuum. For reasons that need not concern us at this point, Leibniz assumed that every well-formed proposition is con- stituted of one subject and one predicate. Relations are recognized as useful but merely "ideal things". In con- sidering the relation "greater than" which is to hold between M and L, he states that "is greater than L" can be considered an accident of M, "is less than M" can be con- sidered an accident of L. but he also realizes that there is a third way of analyzing this proposition. namely by treating the relation "as something abstracted from both". 35Latta, o . cit., p. 21. 36Ibid. 36 In this case It cannot be said that both of them. L and M together are the subject of such an accident; for if so. we should have an acci- dent in two subjects with one leg in one and the other in the other; which is contrary to the notion of accidents. Therefore we must say that this relation, in this third way of considering it, is indeed out of the subjects; but being neither a substance, nor an accident, it must be a mere ideal thing, the considera- tion of which is nevertheless useful.37 Thus, while "is greater than M" refers to a real accident, "is greater than" refers to an "ideal" thing. It seems that the relations owe this shadow of an exis- tence to the pragmatic justification that "their considera- tion is useful", and indeed the knowledge of some of the properties of relations is indispensable for certain calcu- lations Nevertheless, the proper analysis of a statement such as "M is greater than L" resolves it into one subject and one predicate. Thus the only sentences which are considered strictly meaningful are ones that consist of one subject and of an absolute predicate. Let us consider for the moment only singular statements of this kind. Leibniz held that such statements fall into two classes: those 37George Martin Duncan (ed.). The Philosophical Works of Leibniz, New Haven 1890, pp. 266f. Cf. Russell, 0 cit., pp. 12f. 37 that are about what he calls true or substantial units, and those whose subject refers to aggregates. Now the statements about true units have a certain metaphysical prerogative over the others: all others are meaningful if and only if they can be replaced by statements about true units. But what is a true or substantial unit? Leibniz writes: "Substantial unity calls for a thoroughly indivisi- ble being. naturally indestructible."38 Objects which are not so indestructible are said to have no real existence. "What is not really one being (pp etre) is not really a . n 39 . . being (un etre) . From true or substantial units Leibniz distinguishes "beings by aggregation". As examples he cites armies, flocks of sheep. piles of stone. More— over, any extended physical object is considered such a being by aggregation. He says that: A block of marble is no more a thoroughly single substance than would be the water in a pond with all the fish included, even when all the water and all the fish were frozen; or any. more than a flock of sheep, even when all the sheep were tied together so that they could only walk in step and that one could not be touched without producing a cry from all.40 38Letter to Arnauld, in: George R. Montgomery, (ed.) Leibniz, Discourse on Metaphysics, Correspondence with Arnauld. and Monadology, La Salle, 1902. 39Russell, op. cit., 242, Montgomery, op cit., 192. 40Letter to Arnauld, Montgomery, op. cit., p. 161. 38 It is the mind of the observer alone that gives unity to such beings by aggregation. "This mass of sub- stances", he says, does not form in truth one substance. This is a result to which the soul by its perception and . . . . . 41 its thought gives its last achievement of unity." Now Leibniz holds that statements about aggregates can fre- quently be replaced by statements about the components of such aggregates. He points out: It seems that what constitutes the essence of a being by aggregation consists only on the mode of the being of its component elements. For example, what constitutes the essence of an army? It is simply the mode of being of the men who compose it. Apparently, Leibniz was working on a method whereby all statements about couples, trios, etc. can be translated into statements about the members of such couples, trios, 43 etc. Now if such a translation can always be afforded, then no harm can come from asserting something about an aggregate, since such an assertion can always be replaced by an equivalent set of statements about the members of the 41Nouvaux Essais, p. 235 (Bk II. Ch. XXIV). 42Letter to Arnauld, Montgomery, 0 . cit., p. 190. 43Ad specimen calculi universalis addenda, cf. R. M. Yost, Leibniz and Philosophical Analysis, Berkeley 1954, p. 11. 39 aggregate. The question whether or not the aggregate has existence is then a purely metaphysical one, and in deny- ing such existence, Leibniz shows himself as a nominalist.43 On the other hand, if there is a group of statements about aggregates which cannot be translated. in principle, into statements about true units, then the issue becomes some- what more complicated. especially if any important state- ments. such as the enunciations of physics or geometry are included in this latter category. For all statements which are in principle incapable of translation into statements about true units must be considered meaningless in the strictest sense. although practically speaking they may be rather useful. For example, an assertion about a couple of stones can perhaps be translated into statements about the stones in that couple, but these latter statements are themselves about aggregates, the stones being composed, according to Leibniz, of an infinity of parts. Consequently 43In Leibniz, no clear distinction seems to be drawn between the whole-part relation and the class mem- bership relation. When I use the term 'aggregate' I wish to use this term verbally so as to apply to wholes as well as classes. Now Leibniz seems to have desired the exis- tence of classes as well as that of wholes composed of more than one metaphysically simple individual. 40 the statements about the stones are no more about true units than were the statements about the couple. Now if a set of statements about true units can be found equiva— lent to the statements about the stones. then these latter statements are shown to be meaningful in the ultimate meta- physical sense. otherwise they are not. But for such a translation it is not sufficient to develop a method where- by statements about finite aggregates can be replaced by statements about the members of such aggregates. rather. if a precise and strictly meaningful language about physical objects is to be developed. then a method of analysis must be brought forth with which infinite aggregates can be similarly handled. This is a consequence of the assumption of the actual infinite. Does Leibniz hold that such an analysis can, at least in principle, be carried out? I believe that this question must be answered in the negative. But in order to establish this result we will have to examine Leibniz' views on matter. Assuming that a statement about a stone is to be analyzed, what can we say about the ultimate constituents of that stone, and why should it be impossible to replace the original statement by a series. (perhaps an infinite series) about the ultimate parts of that stone? First of 41 all, what are the ultimate parts of which a physical object is composed? These units cannot be particles of matter or material atoms since "every part of matter is. I do not say divisible. but actually divided. and consequently the smallest particle should be considered as a world full of an infinity of creatures."45 This amounts to saying that while we can separate spatially the members of a class of physical objects. we cannot carry out a spatial separation down to the ultimate constituents. Thus while it is possi- ble to divide. ad infinitum. any piece of matter. such a division will not ultimately produce the units out of which that piece of matter is constituted. Rather. the piece of matter is given rise to by entities that do not partake of spatial characteristics at all. Properly speaking, the ultimate constituents of matter cannot even be said to have location in space: Space is the order of coexisting phenomena, as time is the order of successive phenomena. There is no nearness or distance, whether spatial or absolute. among Monads, and to say that they are collected together in one point or dispersed throughout space, is to make use of certain fictions of our mind. by which we try to repre- sent to ourselves in imagination what cannot be. 45Specimen calculi universalis. Wiener. op. cit., p. 99. 42 imagined but only understood.46 In short, the true units or monads to which the subjects of properly constructed sentences must refer, are not bits of matter and are not amenable to any characteriza- tion in terms of spatial properties. Rather. matter "results from" and is constituted by. the ultimate indivi— duals or monads. "Strictly speaking. matter is not com- posed of constitutive unities, but results from them. for matter or extended mass is nothing but a phenomenon founded on things, like the rainbow or the parhelion, and all reality belongs only to unities."47 Thus the analysis of statements about physical objects runs into considerable trouble since the monads are contained in a physical object not in the same way in which an element of a set is "in" that set. Thus it would seem that the rules developed for the analysis of statements about couples. trios, etc. be- come inapplicable not only because the sets here considered are infinite. but because of the peculiar mode of contain-‘ ment of monads in their objects. This has as a consequence 46Letter to Des Bosses, Latta. op. cit.. p. 221. 47Russell, op. cit.. p. 243. 43 that the properties of phySical objects must. for the most part. be considered emergent with respect to the properties of the monads contained "in" that object, i.e. they are not predictable from the properties of the contained monads. This can be demonstrated in the following way. In the Monadology Leibniz introduces a classification of monads intosxnfls and other monads. the souls being dis- tinguished by more distinct perceptions and by the posses- sion of memory?8 Presumably. inanimate bodies. such as stones. do not contain souls among their constituting monads. Now in a letter to De Volder. Leibniz writes that the essence of the pppl_is to represent bodies. One gathers from the context that this is a dis- tinguishing characteristic of souls. i.e. that other monads do not represent bodies. On the other hand. monads are defined as units of perception. Moreover. it is asserted that all monads mirror the universe and therefore in parti— cular also the body in which they are housed. One might conclude that, if all the perceptions of any one monad in any body were known. one would then be able to deduce the properties which such a body would have when considered as 48Monadology, No. 19, Wiener, o . cit.. pp. 536f. 44 a physical or phenomenal object. But this does not have to be the case. If a stone. for example. does not contain any souls among its monads. then it does not contain any monad which perceives the stone spatially in the way in which souls perceive it. That is to say. since the modes of per- ceiving the universe differ in the different classes of monads. it may not be possible to deduce all the phenomenal properties that the stone has in the experience of a soul from the way in which it is perceived by the "bare monads" in the stone. Outside of perceptions each monad is said to have materia prima. Materia prima is said to be that element by virtue of which bodies resist penetration and locomotion. As far as I can see. impenetrability and inertia are the only properties that are found in monads as well as in the bodies which arise from monads and hence are the only pro- perties in bodies which are clearly not emergent with respect to the monads out of which these bodies are con- stituted.49 There is further evidence for the thesis just pro- posed. In the Nouvaux Essais, Leibniz points out: 49Wiener, op. cit.. p. 161. 45 It is to be observed that matter, taken as a complete being is nothing but a collection or what results from it, and that every real collec— tion presupposes simple substances or real unities, and when we consider further what belongs to the nature of these real unities, i.e. perception and its consequences, we are transferred.:u3 to speak, into another world, that is into the intelligible world of substances, whereas beforpO we were only among the phenomena of the senses. The locution that we are "transferred ..into another we world" suggests that Leibniz wished to distinguish as sharply as possible between the phenomenal and the intelli- gible world. But elsewhere he is even more explicit: I believe the true criterion as regards objects of sense is the connection of phenomena, i.e. the connection of what happens in different times and places. and the experience of different men, who are themselves, in this respect, very important phenomena to one another...But it must be confessed that all this certainty is not of the highest degree....For it is not impossible, metaphysically speaking, that there should be a dream connected and lasting as the life of a man. 51 Now if the characteristics of bodies were not emer- gent with respect to the properties of the monads which constitute the bodies,then the particular certainty which Leibniz expresses with respect to his metaphysical scheme would be transferred to statements about phenomena, the 50Nouvaux Essais, p. 428. 51Ibid., p. 422. 46 latter being deducible from the former. However. since statements about the world of experience have only moral certainty. the characteristics of matter as experienced must be. for the most part. emergent relative to the pro- perties of the monads in question. On the other hand. wherever matter is experienced. and wherever such an ex- perience occurs in an orderly connection with other experi- ences. Leibniz assumes monads to be present "in" the matter so experienced. This I take as the meaning of the dictum that physical objects are phenomena bene fundata. Bene fundata does not mean then that the properties of physical objects are all inferable from the properties of their constituting monads, rather. it is to say that physical objects are not mere illusions, but that. wherever a physi- cal object is present. there are monads. It appears that in Leibniz‘ system statements about physical objects were thought to have a function and character akin to those attributed to value judgments by the early positivists; the usefulness of value judgments was never denied. but they were treated as some sort of useful nonsense, irreducible to observation statements, i.e. irreducible to the most fundamental kinds of assertion that the positivists thought could be made. 47 Similarly with statements about physical objects in Leibniz: we must make them in order to get around in the world. In point of fact. Leibniz is most emphatic in sta- ting that the metaphysical analysis of matter contributes nothing to the development of the science of physics and is in no way required to put physics or common talk about physical objects on a sure footing. Leibniz writes: and I grant that the consideration of these forms (i.e. substantial forms or monads) is of no service in the details of physics and ought not to be employed in the explanation of particular phenomena. The physicist can explain his experiments, now using simpler experiments already made, now employing geometrical or mechanical demonstra- tions without any need of the general considera- tions which belong to another sphere, and if he employs the cooperation of God, or perhaps of some soul or animating force. or something else of a similar nature, he goes out of his path quite as much as that man, who, when facing an important practical question, would wish to enter into profound argumentations regarding the nature of destiny and of our liberty. This points again at the wide gap between the phenomenal world of matter and physics and the intelligible p. 52Discourse on Metaphysics, No. X, Wiener, o . cit. 53Ibid., p. 303. 48 world of substances and metaphysics. But why did Leibniz introduce this bifurcation? In Descartes we already find a similar distinction. There. experience is divided into the veridical experience of primary qualities and the illusionary experience of what are called secondary qualities. Descartes undertook this distinction partly in order to explain certain oddities of direct experience: auditory experiences without external stimuli, light sensations without external stimulation, warm and cold sensations simultaneously from the same external source etc. Leibniz, however, had different rea- sons for distinguishing a phenomenal world from an intelli- gible one. It will be noted that in Leibniz the bifurca- tion is much more thorough, in that experiences of extension and duration are also referred to the perceptor rather than the perceived. While Descartes' distinction was to resolve epistemological puzzles, in Leibniz the differentiation is made in order to overcome logical difficulties. in partié cular both the indicated problems of the continuum. How is this result attained? We have seen that statements about phenomenal objects cannot be translated into statements about true units or monads. Nevertheless, Leibniz assures us that it 49 is perfectly proper for the scientist to employ modes of speech that are improper. metaphysically speaking. This assurance, it must be noted again, is not based on the assumption that such improper forms of speech can be replaced by equivalent metaphysically correct expressions, rather. it hinges on the fact that the phenomenal world has a certain order in its own right, that the phenomena occur in orderly sequences and can be described in a practically satisfactory way without recourse to a descrip- tion of the constituting monads. But this pragmatic justi- fication does not guarantee that a description of the phenomenal world will always be free of contradictions. Thus, if bodies are phenomenally continuous, as Leibniz admits, then they have infinitely many parts and thus have proper parts with just as many parts as themselves. This contradicts an accepted axiom. Leibniz argues that the extended when conceived through itself alone. i.e. when considered as a merely phenomenal object. contains a con- tradiction. In order to prevent the arising of this con- tradiction, all statements about physical (phenomenal) objects are declared meaningless in the strictest meta- physical sense. Hence strictly speaking. the contradiction cannot be stated. 50 To summarize the results attained to this point: Leibniz introduces a distinction of phenomenal and intelli- gible world in order to remove a logical difficulty. For, if any piece of material substance is considered as a "veritable whole", then a contradiction arises since this piece of matter is (at least phenomenally) continuous and has therefore infinitely many parts. Consequently, under this assumption it would have a proper part with just as many parts as itself, which contradicts Euclid‘s ninth axiom. Hence a piece of matter. or any extended substance cannot. according to Leibniz, form a "veritable whole", its wholeness is merely illusionary and depends on the parti- cular mode of representation which characterizes souls. Now any statement which presumes that a piece of matter forms a whole, i.e. which makes an assertion about such a piece of matter is. strictly speaking, nonsense, so that the threatening contradiction cannot be stated in the pre— cise language which requires that the subjects of sentences must refer to veritable wholes. While it cannot be said that Leibniz developed a sort of type theory, the strategy is strikingly similar to that employed by Russell. Russell, too, disallows certain. statements which, at first sight seem quite inoccuous, for 51 example "the class of cats is not a cat", and his stipula- tion to consider as nonsense utterly respectable sentences of the natural language in order to keep contradictions from arising seems already to have been employed by Leibniz. But further parallels are hardly justifiable. For one thing. Leibniz' theory contains a good deal of metaphysics. His entities "of lowest type", the monads, are described in some detail, while in Russell's theory it is not further specified of what particular character the individuals on the lowest level are; or even whether there is an absolutely lowest type level. Furthermore. Leibniz' theory is dis- tinguished from that of Russell by the fact that statements which violate the prescriptions for the precision language of monads nevertheless can be justified pragmatically, which allows on the one hand free use of the language of phenomena and on the other hand explains the ultimate insufficiency and inconsistency of this language by its essential imprecision. It seems that what we have called the first problem of the continuum is resolved in a very interesting way by the provisions which have been discussed above. But I have already pointed out that the so-called labyrinth of the continuum actually consisted of two separate problems. The 52 second problem had to do with composition of the continuum and its ultimate elements. Now in the intelligible world of monads no continuum is to be found. Leibniz points out: In actuals there is nothing but discrete quantity, namely the multitude of monads or simple substances, which is greater than any number whatever in any aggregate whatever that is sensible or corresponds to phenomena.54 Thus, continuity can be attributed only to phenomenal objects, and investigations of these phenomenal objects must be carried out in the imprecise language that is inevitable with them. However, one might object that the problem of continuity is really quite divorced from con- siderations of what is real, and that it has only to do with certain order types or with a discussion of the kind of entity that fulfills the axioms of geometry. Under this view the latter is also a purely abstract consideration which is totally divorced from any question concerning the nature of reality. I think that these objections are quite well taken. Only, in the 17th and 18th century geometry was not usually considered an axiomatic system in the modern sense, but a description of space. For Leibniz this meant that geometry had the task of describing the 54Russell, op. cit., pp. 245f. 53 phenomenal world in certain Of its aspects. A word of caution must be uttered at this point. "Phenomenal" for Leibniz did not mean the same as "per- ceivable". When he defines in a passage already quoted in the introduction a continuous line as one where there is a point between any two points. he is speaking about the phenom- enal world. But this does not mean that there is a visually distinguishable point between any two other visually dis- tinguishable points. Rather. this dictum describes a non- perceivable feature of lines; in other words. not all charac- teristics of phenomenal objects are perceptible. This assump— tion. soon to be removed by Berkeley. seems to make it more accurate to say that the phenomenal world is ordered accord- ing to the principles of geometry. and that we can perceive only the grosser features of this arrangement. This means that the theorems of geometry. although descriptive of phenomenal space, are not arrived at through the empirical observation of the phenomenal world. Rather. it is asserted apodicticafly that the phenomenal world conforms to the theorems of geometry. even in those parts that are beyond observation. Leibniz points out that "in order for there to be any regularity and order in Nature. the physical must be constantly in harmony with the geometrical."546 54aLetter to Varignon, Wiener, o . cit.. p. 185. 54 Thus the fundamental assumption that this universe is well arranged, "the best of all possible", leads Leibniz to conclude that geometry must apply without restriction to the physical world, or. to be more specific, that Euclidean geometry thus applies. Now the lines. surfaces and bodies discussed in this geometry are said to have the property of continuity: "Geometry is but the science of the continuous"55 Leibniz points out. Now since geometry and physics are in harmony. physical bodies must also be considered continuous, and this harmony. which is considered a priori certain. would not obtain "if wherever geometry requires some continuation. physics would allow a sudden interruption".56 It must constantly be borne in mind that geometry does not describe the world as it Lg, but only as it appears. or. as Leibniz puts it on another occasion: "continuous quantity is something ideal. which belongs to possibles and to actuals considered as possibles."57 It may have seemed to Leibniz that the eviction of the problem of the continuum from the realm of actuals robbed it of 551bid. 56Ibid. 57Russell. op. cit.. p. 246. 55 its metaphysical sting: there simply is no continuous enti- ty and thus the question as to the composition of the con- tinuum -- if there were one -- becomes rather "academic". But this did not prevent Leibniz from addressing himself to this problem: namely what sort of thing is it that is demanded by Euclidean geometry or, to put it otherwise, what is the composition of the phenomenal continuum of physical bodies. According to Leibniz, when a representation of a continuous quantity takes place in a mind, there is no corresponding continuous quantity "out there". This follows from the distinction of the phenomenal from the intelligible. Hence all that can be said when a mind has such a represen- tation is that a "notion" is present in that mind which may be occasioned through, or occur coincidentally with, the presence of monads. Now one cannot speak of the parts of a notion in the same sense in which one speaks of the parts of an object in everyday discourse. A distinction must be made between what may be called the analysantia of a nOtion and the parts of an object. This Leibniz points out in the following passage: Several peOple who have philosophized, in mathematics, about the point and unity, have become confused, for want of distinguishing 56 between resolution into notions and division into parts. Parts are not always simpler than the whole,5§hough they are always less than the whole. It seems to be Leibniz‘ contention that any given continuum, being nothing but a notion, has no parts which are simpler than itself. This, it seems to me, amounts to saying, that "continuum" cannot be defined through terms denoting entities that are contained "in" continua. This conviction, of course, is bound up with the notion that in a definition the definiens must always consist of concepts that are simpler in some sense than the concept in the definiendum. Leibniz seems to have assumed that parts of a continuum are never simpler notions than the original continuum itself, supposedly because they have to be described as l/2 or 1/4 of the original quantity, etc. Thus the question as to what the phenomenally simple con- stituents of the continuum are, is invalid if what is asked for are entities simpler than the continuum itself; there are no such things. Nevertheless, divisions of a continuum can, of course, be made. But Leibniz contends "there are no 58Russell, op. cit., p. 246. 57 divisions in it but such as are made by the mind, and the part is posterior to the whole".59 This amounts to saying that in a continuous quantity any assignable number of divisions can be carried out, but the resultant parts will never be the constituents of the continuous quantity, if by "constituents" we mean parts that give rise to, or are simpler than, the whole which they compose. This is the strategem by which Leibniz wants to resolve the problem of the composition of the continuum: the continuum is declared not to have parts that can be said to compose it. Rather, its parts are posterior to the whole. However. one might justifiably ask what the difference is with respect to the paradox of Galileo between infinite sets whose elements are defined through the set and sets that are defined through its elements. It seems that this distinction makes no difference whatever. Thus. if a line has infinitely many parts which are posterior to the whole, the paradox arises just as much as it does if the parts are anterior to the whole. It seems to me that it is not even necessary fully to understand the anterior-posterior distinction here, introduced by Leibniz in order to see that the stragegem 59 Russell, op. cit.. p. 245. 58 is of no avail. The paradoxof Galileo. successfully defeated in the intelligible world rears its ugly head in another world. However, I believe that Leibniz can be defended. If .the divisions of a continuum are, so to speak, man made, then one cannot say that a continuum has any more parts than are actually produced. and this number is, of course, always finite. If this is what Leibniz had in mind, then we may say that the problems of the continuum are, after a fashion, removed. At any rate, the solutions which Leibniz offers and which I have attempted to indicate on the pre- ceding pages are more ingenious and comprehensive than any subsequent ones down to the time of Bolzano. One of the questions that remains to be resolved is how Leibniz justified the fact that geometricians, he him— self not excluded, availed themselves freely of the notions that a line is infinitely subdivisible, that it contains an infinite number of infinitesimals etc. The justifica- tion for these procedures is entirely pragmatical, as I have indicated above, and seemed to satisfy Leibniz fully In the New Essays, Leibniz writes: You (Philalethes -- Locke) deceive your- self in wishing to imagine an absolute space, which is an infinite whole composed of parts; 59 there is none such. it is a notion which implies a contradiction. and these infinite wholes. and there opposed infinitesimals, are used only in the calculations of geometers. just like the imaginery roots of algebra. Of course, that these calculations are successful is patent to every observer, and therefore Leibniz seemed to believe the fictions contained in the calcula- tions must be condoned. Some commentators seem to believe that Leibniz, in claiming that there really are no infinitesimals already had an inkling of the foundations of the calculus that were to be laid much later with Couchy and others. Boyer. in his Concepts of the Calculus writes: A rather inexact tradition would impute to Leibniz a belief in actually infinitesimal magnitudes. However Leibniz himself. in a letter written about two months before his death, said emphatically that he 'did not believe at all that there are magnitudes truly infinite or truly infinitesimal'. These conceptions he regarded as 'fictions useful to abbreviate and to speak universally'.61 The preceding investigation points at the sense in which this remark is to be taken. Of course there are no infinitesimals in reality. The intelligible. real world 6ONouvaux Essais. p. 163. 61Carl B. Boyer, o . cit.. p. 219. 60 contains no such things. But as far as the phenomenal world is concerned they can be justified, so Leibniz seemed to believe, just as much or just as little as other geo— metrical entities, such as continuous lines. Thus the repudiation of infinitesimals was not brought about through predominantly mathematical considerations, but followed from a certain metaphysical position, which in turn, it must be pointed out again, was adopted in order to overcome certain logico-mathematical difficulties. Let me now briefly indicate the significance of the foregoing investigation. I have attempted to show that Leibniz' metaphysical system was adopted, to a large extent, in order to overcome certain logical difficulties. If I have succeeded in doing this, I have at the same time shown that here is a system of metaphysics in which cer- tain seeming logical paradoxes cannot arise. and I have reason to suppose that other metaphysical systems of the same and subsequent eras were developed with similar pur- poses in mind. Of course I have not attempted to give an exegesis of Leibniz' entire system, but a great number of its features have been discussed. and a great number of others would seem to follow immediately from the points mentioned. 61 For example in the beginning of the Monadology Leibniz writes: There is also no way of explaining how a monad can be altered or changed in its inner being by any other creature. for nothing can be transposed within it. nor can there be conceived in it any internal movement which can be excited. augmented, or diminished within it, as can be done in composites. where there is change among the parts. The monads have no windows through which anything can enter or depart. Thus it can be seen that the assumption of actual independence of the created monads from one another is an outgrowth of the View that the monads have no parts. an assumption which we saw above to be indispensible for the resolution of the problems of the continuum. The lack of windows in monads, in turn. requires the introduction of the notion of the preestablished harmony in order to explain the succession and presence of representations within the individual monads. Thus other parts of Leibniz' system, although not themselves required to resolve the problems of the continuum, would seem to follow at least in Leibniz' opinion, from the assertions which were made in order to keep those problems from arising. This gives us all the 62Monadology. N). 7, Wiener, o . cit.. pp. 533f. 62 more reason for supposing that those parts of the system which are connected with the problems of the continuum are the ones which are closest to the problem for the sake of which the whole scheme was developed. The foregoing pages have shown Leibniz' philosophy to be a very complicated and intricate system. In the sequel. I shall examine solutions to the problems of the continuum offered by Bayle and Berkeley which are much more radical and also much simpler than Leibniz‘ CHAPTER II GEORGE BERKELEY I now wish to discuss the ways in which Berkeley dealt with the problems of the composition of the continuum. To this end it is necessary to remove certain prevalent misconceptions concerning Berkeley's philosophy and its development. For example, Berkeley's interest in mathe- matics has sometimes been doubted despite the fact that a very large proportion of his studies are concerned with mathematical topics. A certain amount of mathematical interest has sometimes been conceded to him, but his mathe- matical ability has usually been considered extraordinarily poor. Hand in hand with these attitudes has gone the notion that Berkeley's motives for developing his imma- terialist philosophy were largely of a moralist or theologi- cal character. Occasionally, too, Berkeley is considered to be one of the philosophers, in a long line of system builders, who do not have much regard for extraphilosophical problems or for the application of a philosophical scheme to the world at large. All of these interpretations I hold to be mistaken, 64 and I will try in the sequel to disprove them in detail. In addition, I wish to show that the resolution of the problem of the continuum. as far as we can now discern, was one of the chief motivations for developint his immaterialistic metaphysics. The consistent application of his principles led him to develop a geometry that is very odd. indeed, but the mere fact that the application of his principles is consistent have led me to consider his mathematical ability with greater respect than seems customarily the case among his commentators. Let us consider first the frequently held view that Berkeley's immaterialism was inspired mainly by moral and theologicaldesires. This notion is bluntly, if not very aptly, expressed by Mr. Butler, who points out in his Philosophy of Berkeley. To Berkeley's mind it (i.e. the doctrine of an external material world) is the main prop for scepticism, atheism and materialism. As a good Bishop he is therefore eager to establish the View that only spirits and their ideas exist. 63 Iflr. Butler has here expressed in a singularly forthright Inanner what seems to me a widely held opinion concerning tflae origin of Berkeley's system. Ever since Kant (Critique 63 Benjamin Butler. PhilOSOphy of Berkeley, Boston, l957,p.2. 66 themselves. since their doctrine has certain inconsistent consequences which reduce the whole system to absurdity and should leave the adherent of such a system suspended in a state of doubt. i.e. should make him a skeptic. It must be borne in mind that Belkeley's arguments contra skepticism can be employed by any scientist who replaces a given scientific generalization by another because the former lead to inconsistencies or was inconsistent with (zertain other statements believed to be true. But the fact 'that a scientist can use such an argument. and the fact "that Berkeley did use it. explains in no way the form and (zontent of the respective theories. As to the second point, namely that Berkeley's inmaterialism was advanced because the contrary doctrine ssupports atheism, it must be agreed that Berkeley believed 1ihat a major result of his philosophy is the demonstration <>f the untenability of atheism -- he gives a well-known I>roof for the existence of God and in general expounds tliis feature of his philosophy generously and repeatedly. Eth one cannot sanely assume that this demonstration was at) only, or even a major, motive for the development of "tflle immaterial hypothesis." Moreover. many Christian aPologists have made it their aim to disprove atheism 65 of Pure Reason B 71) mocking critics of Berkeley have felt called upon to refer to him as "the good Berkeley" or "the good Bishop Berkeley". It may not be out of place to point at the exceptional inappropriateness of this faintly super- cilious epithet where Berkeley's philosophical insight is discussed. It must furthermore be pointed out that Berkeley only became a bishop more than two decades after the Principles were published. To be sure. at the time of the publication of the Principles he was ordained. but the ordination was a routine part of the academic career of the fellows at Trinity. Let us consider Butler's explanation of the origin of Berkeley's immaterialism in some detail. First it is said that the contrary doctrine, namely that there is an external material world. furnishes support fOr skepticism. One might be lead to think that skepticism was rampant at lBerkeley's time, and that he set out to develop a theory tfliat would not give rise to it. But such clearly was not tflie case. The first dialogue between Hylas and Philonous InaJces it amply clear that the man alleged to be a skeptic VWBS jBerkeley himself and that, by way of a counter attack he arttempts to establish that those adhering to the doc- tririea of an outside material world ought to be skeptics 67 without thereby being led tova philosophy of immaterialism. The third point made by Mr. Butler. namely that Berkeley advocated his immaterialism because it would disprove materialism is too trivial to need any comment. In summary, the notion that Berkeley was posed against materialism be— cause of certain religious and moral convictions concerning its connection with skepticism and atheism gives no reason- able explanation of the development of Berkeley's system. More serious students of Berkeley have attempted to "explain" the genesis of hissuetam by pointing to his dependence upon Locke and Malebranche 64 These eminently worthy pieces of historical scholarship suffer from the one-sidedness of treating philosophy as something like an intramural affair. a viewpoint that is perhaps appropriate for a discussion of the German Idealists. but certainly out (3f place where Enlightenment philosophers are under dis- cuission. There can be no question that Berkeley was influ- ernced by both Locke and Malebranche, but the mere tracing of .lines of historical development will not answer the Queustion why Berkeley differed so significantly from both 64Cf. R. I. Aaron, "Locke and Berkeley's Commonplace 300k", Mind, N.S. Vol. 40, 1931, pp. 439-459. A. A. Luce, §2££§23gey and Malebranche, London, 1934. 68 these philosophers. Obviously, there were certain diffi- culties which, to his mind, neither of these systems resolved. A reconstruction of the context of the develop- ment of Berkeley's philosophy can therefore not be complete without an identification of these problems. A third group of commentators who concerned them- selves with the genesis of Berkeley's system is formed by those philosophers who are reluctant to search at all for a reason behind the adoption of the immaterial hypothesis, who treat this adoption as some sort of spontaneous, uncon- sidered act. This orientation leads to the assumption that Berkeley's immaterialism must be considered as something like an unmotivated fabrication whose author subsequently tried, with considerable difficulty, to reconcile it with 111s experience and the body of knowledge that he had :therited. Johnston expresses this viewpoint most clearly: No harsh Socratic maieutic was needed to bring it (the New Idea) to the birth; it came to light easily and almost imperceptibly, and as we scan the sentences in which Berkeley indicated the process, it is easy to sympathize with his joy and surprise as he gazes at the child of his mind.6 65G. A. Johnston, The Development of Berkeley's W, London, 1923, p. 20. 69 This naive view has at once the most adverse con- sequences as regards the appreciation of Berkeley's system. Immaterialism becomes an apergu, a mere playful invention, which can hardly be justified in view of its results upon geometry. Johnston writes: His willingness to throw overboard the solid achievements of the established geometry simply because they did not accord with an apergu of his own does not encourage to rate his mathematical ability very highly. 6 I believe that Johnston's approach to Berkeley's philosophy is misguided. His way of considering philoso- phical systems would have been appropriate for a discussion of some German philosophers of the early Nineteenth Century whose systems can perhaps be described as free creations. It is known that Schelling occasionally produced philosophi- cal systems so rapidly that some of his products were :superceded by others before they had a chance to appear .in.print. The editor of one of the editions of Hegel's Eflailosophy of Law attacks critics of Hegel who point out trust Hegel's system does not agree with the facts by say- ing; that "systems can only be refuted through other sys- tenus "67 Implicit in this statement is the notiOn that 66Op. cit., p. 90. 67Hegel, Werke, 2nd. ed., Berlin 1840, Vol. 8, Ed. Eduard Gans, p. xrv. u,. 70 system-building philosophers are not concerned with problems found in the sciences, in mathematics. or in everyday life. and that therefore an appeal to facts cannot lead to a refutation of their systems. For the philosophers of the Enlightenment it can generally be said that their systems had the purpose of resolving certain problems which are encountered in everyday experience. in the sciences or in mathematics. It is. therefore. of the turmost importance that the commentator become aware of the extraphilosophical problems which are the raison d'étre and mainspring of these philosophical systems. A deficiency in this respect is a very serious failure. Let me remark here parentheti- cally that Cartesianism was thrown into its deepest crisis ‘Vhen it was discovered that a reasonable system of physics rnust assume that a force is required to change the direction (of a motion. The philosophers of that age took this extra- pfliilosophical discovery seriouSAenough to abandon all attempts of? rescuing Descartes‘ unsatisfactory attempts at explaining the; interaction between mind and body. Johnston's psychological thesis of spontaneous creation has .its systematic counterpart in the notion that Berkeley's fundennental assumptions have none or "few" arguments in its favoir. This view is expressed by C. R. Morris, who writes: 71 "He (Berkeley) expounded his system boldly and shortly, offering in the first place very few arguments in support of it except that of its obviousness."68 Since Morris never states what Berkeley does in the second place, and since he never states the few arguments aside from obvious— ness, we must assume that he was unable to find any. It seems likely that Morris cannot find any such arguments because he is, so to speak, looking in the wrong direction. Let me insert at this point a general consideration as to what kind of argument may be required in order to make a philosophical system or thesis plausible, and where one should look to find "arguments in favor" of a given thesis. It seems that what Morris is looking for are ante- <:edently established propositions of which the thesis or asystem is a deductive consequence. But this procedure, arlthough frequently employed by commentators. is not always iri order. since it is not always possible to produce argu- nmnits of this sort. But if no such premises are offered, it cioes not. therefore. follow that the system in question 68C. R. Morris, Locke, Berkeley, Hume, London, 1931, P. 625. bus. huff-I - I. h... _. 72 has none or "few" arguments in its favor.69 I submit that Berkeley's system is to be envisaged in much the same way as a high level scientific generaliza— tion Its support is to be found in its deductive con- sequences and their truth rather than in premises from which it follows, There is much evidence in Berkeley's writings to the effect that he wanted his philosophy to be considered in this light. In the Philosophical Commentaries, entry no. 207, he states: My end is not to deliver Metaphysiques altogether in a General Scholastique way, but in some measure to accommodate them to the Sciences and show how they may be useful in Optiques, Geometry etc. Generally, the statements in which Berkeley attempts to justify the immaterial hypothesis always stress the fact that the consequences of his thesis are more desirable, explain more, or are less paradoxical, than the consequences of the rival materialist thesis. For example, Berkeley's 69(Of course, I do not wish to claim that the pro— cedure criticised apropos of Berkeley's system is always out of order. If a philosopher claims that the evidence for his system rests with a number of "self-evident” pro- positions, then his claim will have to be examined. But Berkeley never argues in this vein). 70A. A. Luce and T. E. Jessup, (eds.), The Works of George Berkeley, London, 1948, Vol. I, p. 27. 73 claim that the problems of the continuum do not arise in his system is well enough known. It must here be emphasized that this alleged (ctmappearance of the problems of the continuum is one of the results of the immaterial hypothesis and is as such offered in support of the thesis. The analogy between certain philosophical systems and scientific generalizations will help us to clarify another point. Scientific generalizations are generally put forth in an attempt to remove certain problems, to ex- plain certain lower level propositions. These problems, or the assertion of such propositions, can be said to occasion the higher level generalization. While the occasioning of such problems is, perhaps. of small logical importance, its recognition is indispensible for the reconstruction of the context of discovery. For the philosophy of science such reconstructions may be dispensible.‘ Not so in the history of philosophy. Berkeley is a case in point. On a success- ful reconstruction of the context of his discovery of the immaterial hypothesis hinges the answer to such questions as "was the immaterial hypothesis an ppegpp_that was only subsequently and with difficulty reconciled with experience and mathematics?“ or "was it a hypothesis specifically introduced in order to resolve certain difficulties in our 74 account of experience or mathematics?" I am convinced that the latter is the case. and that the problem of the con- tinuum was the particular occasion for Berkeley's introduc- tion of the immateralist hypothesis. It is now incumbent upon me to demonstrate in what way the problem of the continuum influenced the development of Berkeley's metaphysics and to what solution the problem was brought. Berkeley's solution is familiar in kind to those of some modern analytic philosophers: he declares the problem of the continuum to be a pseudo-problem. Con- tinuous quantities had been described as being infinitely divisible i.e. as having more than a finite number of parts. Galileo had shown, and Berkeley knew, that infinite sets have proper subsets with as many members as themselves. That Berkeley was familiar with this result is attested to in the following passage from the Philosophical Commentaries. "The infinite divisibility of matter makes the half have an equal number of equal parts with the '71 , , . . . . . whole.‘ This is at variance w1th Euclid's ninth aXiom. Hence the difficulty. In Berkeley it is resolved, as we shall see, through the assumption that there are no 71 Entry 322, The Works of George Berkeley, Vol. I, p. 39. 75 entities which fit the description given above of continuous quantities. Hence, if there are no entities of this sort. then the question what it is that they are composed of is invalid, is a pseudo—question. Berkeley's solution may here be sketched in a few words. The problem is construed as being concerned with the composition of extended sensible objects. These can be said to be continuous in appearance. "continuous" here referring to a certain phenomenal characteristic. I hesitate to hazard a definition of "continuous", but by way of example it can be said that a figure is visually continuous if it is uniformly colored. Similar criteria inay be set up for phenomenal continuity in the tactile field etc. and eventually one may arrive at a definition c3f phenomenal continuity in general. However, since Iierkeley nowhere attempts to produce such a definition, a rweconstruction of his system runs into rather formidable describe the various relations obtaining between con- tiJauous figures and lines. etc. Geometry is thereby made ari emmflxical science. It is to discuss certain aSpects of serrscuy'experience. It does not concern itself with ixufiJiitely divisible lines and figures. but only with the Phenomenal pseudocontinuum. It seems that Berkeley took serixbusly the theory that geometry is concerned with des- Cril>idig the space of our experience, and it is perfectly JUStifiable to say that this space contains nowhere any I1 . ‘ ~\u 77 subspace of which it can be empirically ascertained that it it has infinitely many parts. A serious criticism of Berkeley's views on this sub- ject can only proceed from the assumption that it is not the aim of geometry to describe empirical space. The construction of such a geometry, of course, is in part mm. arbitrary and, in particular, it can be so constructed that it speaks of spaces. surfaces and lines which have infin— itely many parts. It speaks well for Berkeley's mathe- matical ability that he was willing to countenance such a geometry, but, since it would largely consist of asser- tions not referring to matters of empirical fact, he places aagainst it a moral injunction, to wit. that it is not worth- vihile to investigate matters without practical value. If ciifficulties and inconsistencies arise in such a geometry, tliey can no longer be said to arise from an inability to h‘o arialyze matters of empirical fact. We could summarize Berkeley's opinions on this subject by saying that it was Of small concern to him that some mathematicians have con- StIWJCted a system called geometry, the difficulties of Whitih.they were unable to resolve. On the other hand, he ClaiJns that: Whatever is useful in geometry, and 78 promotes the benefit of human life, does still remain firm and unshaken on our Principles; that science considered as practical will rather receive advantage than any prejudice from what has been said...For the rest, though it should follow that some of the more intricate and subtle parts of Speculative Mathematics may be paired off without any prejudice to truth, yet I do not see what damage will be thence derived to mankind. The above gives in essence Berkeley's solution to the problem of the continuum. In summary, what is con- sidered is not the continuum as later defined e.g. by Dedekind, but a phenomenal continuum not further defined. .Any figure that is continuous in this sense is said to con- sist of a finite number of minima sensibilia, smaller than Vihich nothing can be. This result follows from the princié gale that esse est percipi. This being the case there can hug no actual infinite, and the paradox of Ce ileo cannot .airise with respect to actuals. Thus geometry as the science c>fF empirical space is vindicated. Against "speculative geometry" Berkeley places a moral injunction. We thus find ill lBerkeley the same attitude that we could observe in LGiJJniz: the problems of the continuum were felt to be 72Principles of Human Knowledge, No. 131. Wherever Ber1 extension. Entry No. ll says "Extension not infinitely 89The Works of George Berkeley, Vol. I., p. 9. 93 divisible in one sense.90 I would presume that Berkeley held at the time that there was another sense in which one could speak of extenSion as infinitely divisible. This means that time and extensionl are not infinitely divisible, while duration and extensionz are. Time and extensionl would be phenomenal time and space, duration and extensionz would be the abstract time and space of Newtonian physics. The puzzlements connected with the continuum can occur in the latter, but they are exorcised from the former, simply because neither phenomenal time nor phenomenal space form a continuum. But the problem is not thereby resolved. It is merely extradited from the phenomenal sphere, and retains all its severity in the realm of absolute space and time. It is not until these latter are denied any existence that the problem of the continuum is made to disappear. Entry No. 26 states “Infinite divisibility of extension does suppose ye external existence of extension, but the latter is false, ergo ye former also.\"91 This terse modus tollens argument announces the solution that Berkeley gave to the problem of the continuum: he denied 9°Ibid. 91 Ibid., p. 10. 94 that there is absolute space or duration, and assumed that the phenomenal time and space are not infinitely divisible. However, the doctrine here brought forth is not with- out its difficulties, as Berkeley well realized. For one thing, its repercussions on classical geometry become at once apparent. Entry No. 29 says "Diagonal incommensurable with ye side Quaere how this can be in my doctrine?"92 This entry bespeaks the fact that at this point Berkeley still meant to bring about a reconciliation of his doctrine with classical geometry. The entry in fact asserts the incommensurability of the diagonal with the side, but the inconsistency of this theorem with his doc- trine is realized. How does he resolve the inconsistency?. A large number of entries deal with the problem,93 but of especial interest are entries 263 and 264. 263 states: "Mem: To enquire most diligently Concerning the Incommen- surability of Diagonal and side. Whether it does not go on the supposition of unit being divisilbe ad infinitum, i.e., of the extended thing spoken of being divisible ad 92Ibid. _ 93See Nos. 249, 250, 258, 263, 264, 276, 340, 457, '469, 470, 481, 500, 510, 516. 95 infinitum..."94 and the next_entry states flatly: "The Diagonal is commensurable with the Side."95 Here the decision is made. To achieve consistency classical geometry is declared in error. Of course, this not only holds for particular theorems of geometry but for the whole mode of approach associated with Euclidian geo- metry. ACCOlding to Berkeley geometry is to be transacted as an empirical science. This becomes evident in entry 249: Particular Circles may be squar'd, for the circumference being given, a Diameter may be found betwixt which and ye true there is not any perceivable difference, therefore there is no difference. Extension being a perception and perception not perceived is a contradiction, nonsense, nothing. In vain to allege the difference may be seen by Magnifying Glasses. For in that case there is ('tis true) a difference perceived but not between the same ideas but others much greater entirely different therefrom.96 This passage is remarkable not only because of the assertion concerning the ratio between the diameter and circumference of'a given circle, but also because it explains how the assumption of external matter could lead 94 ' The Works of Gegrge Berkeley, Vol. I, p. 33. 951pid. 96Ibid., p. 31. 96 to the thesis of infinite divisibility. For Berkeley, the sensation that we have when we look at a circle through a magnifying glass cannot be said to be "of the same object" than when we look at the "same" circle with the naked eye. Hence magnifying glasses will not allow us to discern parts in a minimum visibile that we sensed in a previous sight experience with the naked eye. If we assumed the contrary, then we would have to agree that more powerful magnifying instruments might produce still larger images of the fsame" object, and that we could then discern parts that were not seen before, etc. Unless an absolute limit of magnifica- tion can be demonstrated, this would lead to precisely the problems that the immaterial hypothesis was meant to remove. The above analysis has shown that Berkeley's solu- tion to the problem of the continuum depended crucially upon the notion of the minimum sensibile (visibile, tangibile, etc.). Whenever a specific problem of a geo- metrical nature arises, e.g., the squaring of a particular circle or the ascertainment of the length of the diagonal of a given square, then we ought to proceed, according to Berkeley, by counting the minima sensibilia out of which these figures are said to be composed. The minima 97 sensibilia, being the smallest perceptible units, have no perceptible parts and therefore, according to Berkeley, no parts at all. But since they are perceivables, they have some magnitude so that a line or a shape is always made up of a finite number of them. But a peculiar diffi- culty arises at this juncture. Warnock puts it in the following way: He (Berkeley) says that there is an idea nothing that is not actually discerned in it. But certainly a line drawn on paper is not gegg_as composed of a definite number of points; it looks continuous. It is not only that one has no idea how to make even a reasonable guess at the number of points in a line; it does not look as if it were made up of points at all. And should not Berkeley have concluded that it i§_not made up of points? The difficulty here exposed cannot be resolved by referring to Berkeley's theory of abstraction. It is well enough known that he countances only one mode of "abstrac- tion” and that it is the imagining of parts of complex ideas of perception. He says: I find indeed I have a faculty of imagining, or representing to myself, the ideas of those particular things I have perceived, and of variously compounding and dividing them...To be plain, I own myself able to abstract in one sense, as when I consider some particular parts 97G. J. Warnock, Berkeley, London 1953, p. 219. 98 or qualities separated from others, with which, though they are united in some object, yet it is possible they may really exist without them. 98 As concerns the number of points in a line it is precisely the question how many parts there are to the line that can really exist (i.e., exist in perception) without the rest being around, and before this is ascertained no subdivision of the line into smallest parts can be carried out in imagination. As far as I can see, Berkeley nowhere suggests a solution to the difficulties here indicated. A solution might be found if some kind of operation were indicated through which the division of a line or surface into minima visibilia or pangibilia might be affected. But even then considerable oddities would remain. Berkeley repeatedly uses "point" and "minimgm visibile" in the same sense. For example in the New Theory of Vision he says: No exquisite formation of the eye, no peculiar sharpness of sight, can make it (i.e., the minimum visibile) less in one creature than another; for, it not being distinguishable into parts, nor in anywise, consisting of them it must necessarily be the same to all. For suppose it otherwise, and that the minimum yigibile of a mite, for instance, be less than the minimum visibile of a man; the latter 8 Principles of Human Knowledge, Introduction, No. LWO. lO. 99 therefore may, by detraction of some part, be made equal to the former. It doth therefore consist of parts, which is inconsistent with the notion of a minimum visibile or point. Assume that, as a matter of empirical fact the smallest perceivable blotches of a certain color, say green, are always oblong. Now if we were to say that green minima visibilia are always oblong, we would be at variance with Berkeley as quoted above, since it would be clearly false that such an object does not in anywise consist of parts. We can always find a statement that is true of one side of such a shape but not of the other, and we thereby gain a procedure of distinguishing parts in such a shape. If this holds and yet there is no perceptible green speck smaller than certain oblong shapes, we are forced to the conclusion that there are no green mipima visibilia, because the shapes described are no migime_since there is a sense in which parts can be distinguished in them, and they cannot be subtracted from since they would then no longer be visibilia. Under the above assumptions a geo- metry in Berkeley's sense of green objects would be quite impossible, since no ascertainable relations of magnitude 99Essaytowards A New Theory of Vision, The Works 53f George Berkeley, Vol. I., pp. 159-239, No. 80., p. 204. 100 obtain between green objects, magnitudes being compared by counting minima sensibilia. But this is clearly false. We may, after all, measure the length of green lines as well as the length of lines of any other color. Thus the assumption that there are parts in the smallest visible green specks must be false. In order to salvage the rest of the system we shall have to say that green minima visibilia are oblong. The consequences of this assumption, however, are quite strange. For one thing, green geometry would differ from the geometry of shapes of other colors. It is conceivable, moreover, that a green square may be produced the length of whose side is one minimum sensibile. The difference between the length of the diagonal of this square and a minimum visibile is smaller than one minimum visibile, hence there is no difference. Another square may be produced whose diagonal has the length of two minima visibilia precisely. The difference between the length of its sides and one minimum visible is smaller than a minimum visibile, hence there is no difference. In the first case 'a‘was equal to l, in the second case it ‘fias equal to 2. In other squares it will vary between tihese two values. One can safely assume that this is VVIeaking more havoc in geometry than Berkeley intended, but 101 if Geometry is to become an empirical science, it will have to put up with all manner of empirical conditions. Surely, since a set of statements that accurately describes the world or part of it is always consistent, Berkeley's geo- metry will be consistent. But one must hope that Berkeley's method is not the only one of removing the apparent incon- sistencies of the continuum: Were it not for the fact that an inconsistent geometry always entails Berkeley's geometry, one might even be tempted to put up with inconsistencies. A consideration of the above sort has some merit in that it throws doubt on the alleged generality of geometri- cal proofs in Berkeley's system. A geometrical proof, according to Berkeley, is conducted on some particular figure, but it becomes general, i.e., holds for all figures which have all those properties that are explicitly mentioned in the given proof. In all other aspects they may vary from the figure used in the demonstration.100 But it seems now that if Berkeley's program of turning geo- metry into an empirical science is to be taken seriously, certain empirical properties of the paradigm figures other. than those customarily advanced in geometrical demonstra- tions might have to be considered. It is a problem that loogginciples of Human Knowledge, Iggroduction. ‘V" 102 must be empirically investigated whether or not these empirical properties, e.g., color, do or do not make a difference. Only within the limits indicated by such an empirical investigation may we say that "any theorem may become universal in its use."101 Let me include here a brief summary. I think that I have shown the reasons for the adoption of the immateri- alist hypothesis to lay with the fact that it avoids the problems of the continuum. To paraphrase Berkeley: on one hand, no demonstration can be given for the existence of external matter, but on the other hand, its rejection removed the difficulties of the infinite.102 But'Berkeley's solution is obtained at the expense of having to put up with a system of geometry of a rather strange nature. How- ever, I believe that any attempt to construe geometry as an empirical science in Berkeley's sense will run into similar difficulties, a very good reason not to consider geometry an empirical science. With the proposal of immaterialism and the postula- tion of a new basis for geometry Berkeley's task was not Ibid , No. 128. lpgg., No. 133. 103 completed. He had to concern himself with the obvious fact that mathematical analysis, working with the assump— tion of infinite divisibility of lines, etc., and with the assumption of the existence of infinitesimals had been overwhelmingly successful. According to Berkeley, analysis as then conceived was premised upon erroneous assumptions. This is at first dogmatically asserted in the Philosophical Commentaries, the Principles and the Dialogues Between 103 Hylas and Philonous, and later on proved in the Analyst. In the Analyst Berkeley presents two sets of arguments against the Calculus. The first depends upon his own theory of abstraction as put forth in the introduction to the Principles. Query No. 4, at the end of the Analyst, asks "whether men may properly be said to proceed in a scientific method, without clearly conceiving the object they are conversant about...?"104 and Query 9 reads "Whether mathematicians do not engage themselves in disputes and paradoxes concerning what they neither do nor can 103 The Analyst or A Discourse Addressed to an Infidel Mathematician, first printed in 1734, The Works of George Berkeley, Vol. IV, pp. 53-103. 104281., p. 96. 104 conceive?"105 According to Berkeley, what can be conceived are ideas which must be considered in analogy to sense-data. In this sense, of course, infinitesimals or velocities in a point cannot be conceived. Therefore Berkeley's critical attitude. I believe that these objections had a rather salutory effect in that they made it quite clear that the foundations of analysis did not lay, and should not be sought, in the world of sense experience. But Berkeley's error is quite apparent: whether or not the symbols used in mathematical analysis in fact refer, or can be made to refer, to sensory experience is of no concern to the mathematician qua mathematician. It suffices that they be well defined, except for the primitive terms, and that all deductions proceed according to the laws of logic from the accepted axioms. Thus these objections of Berkeley's, while consistent with his philosophy and general approach to mathematics were really beside the mark. But there is a second kind of objection raised in the Analyst which must be taken more seriously. They consist in detailed studies and criticism of particular 105Ibid. 105 arguments put forth by Newton and Leibniz. Berkeley is able to show that there is at least a good deal of im- preciseness contained in the proofs which he considers. Let me give one example: Let the quantity x flow uniformly, and be it proposed to find the fluxion of x“. In the same time that x by flowing becomes x+o. the power xn becomes (x+o)n, i.e., by the method of infinite series xn + noxn-l + nn - n ooxn_2 + etc., 2 and the increments o and noxn-l + nn-l ooxn"2 + etc., 2 are to one another as l to an-l 4 2? - n oxn"2 + etc. 2 Let now the increment vanish, and their last proportion will be nxn-l. But it should seem that this reasoning is not fair or conclusive. For when it is said, let the increments vanish, i e., let the increments be nothing, or let there be no increments, the former supposition that the increments were something, or that .there were increments, is destroyed, and yet a consequence of that supposition, i.e., an expression got by virtue thereof is retained.106 Berkeley's reasoning is that the division undertaken in order to obtain the third line of the above proof pre- supposes that zero is not equal to zero, while later on, 106Ibid., No. 13, p. 71f. 106 when all but the first member of the infinite series are cancelled, zero i§_assumed to be equal to zero. The point I wish to make here is not that all computations of the derivative of xn are open to Berkeley's objection, but that in point of fact the status of the differential zero in the calculation was not clear at the time, and that some mathematicians went so far as to claim that for the purposes of the differential calculus a division by zero is permissible. Berkeley brings forth arguments similar to the one above, against other methods of arriving at derivatives, and his criticisms are generally sound. The Analyst has been said to mark "a turning point in the history of mathe- matical thought in Great Britain",107 and Boyer points out "Berkeley's criticism of Newton's propositions was well taken from a mathematical point of view, and his objection to Newton's infinitesimal conceptions as self-contradictory 108 was quite pertinent." It must be noted that Berkeley's l 07Florian Cajori, A History of the Conception of Limits and Fluxions in Great Britain from Newton to Wood- house, Chicago 1919, p. 89. cf. Also The World of Mathema- pipe, ed. James R. Newman, N. Y. 1956, Vol. I, p. 286. For the importance of the Analyst in the history of mathematics cf. also Gerhard Stammler, "Berkeley's Philosophie der Mathematik", Kentstudien, Erganzungsheft No. 55, Berlin, 1922. , 108Carl B. Boyer, The Concepts of the Calculus, p. 226. 107 criticism was not so much directed against the mathematician as an "artisan" whose procedures are justified by their results, but against the mathematician qua logician. He says: To prevent all possibilities of your mis- taking me, I beg leave to repeat and insist, that I consider the geometridal analyst as a logician, i.e., so far forth as he reasons and argues; and his mathematical conclusions, not in themselves, but in their premises; not as true or false, use— ful or insignificant, but as derived from such principles, and by such inferences. And, of as much as it may perhaps seem an unaccountable paradox that mathematicians should deduce true propositions from false principles, be right in the conclusion and yet err in the premises; I shall endeavor particularly to explain why this may come to pass, and show how error may bring 109 forth truth, though it cannot bring forth science. The doctrine here indicated is that the results of compu- tations in the differential calculus gain their truth and value from a cancellation of erros, a doctrine that we need not discuss here. That Berkeley was correct in his objections was finally borne out when the foundations of analysis could be laid entirely without the introduction of actual in- finitesimals solely through a consideration of limits. It must be pointed out, however, that the later theories 109The Analyst, No. 20, p. 76f. 108 concerning the foundations of analysis, although doing justice to Berkeley's objections against Newton and Leibniz, did not incorporate any of his positive suggestions: none of them assumes that a line or surface ultimately consists of certain finitely extended particles. What were Berkeley's positive suggestions concerning the foundations of analysis? In his earlier writings he asserts that on the adoption of his principles none of the advantages of the modern analysis will be lost and he points out that mathematicians really deceive themselves when they think that they actually consider infinitesimals: Whatever mathematicians may think of Fluxions, or the Differential Calculus, and the like, a little reflexion will show them that, in working by those methods, they do not conceive or imagine lines or surfaces less than what are perceivable to sense. They may indeed call those little and almost insensible quantities Infinitesimals.... But at bottom this is all, they being in truth finite; nor does the solution of problems require the supposing of any other. In connection with this passage, emphasis must be put on the phrase that mathematicians "in working with those methods“ do not conceive, etc. Berkeley seems to mean by this that the mathematician, as soon as he employs the methods of the calculus in order to produce a drawing or lloghe Principles of Human KnowledgeL No. 132. 109 in order to solve a practical problem must finally speak of, and consider only, finitely extended quantities. Berkeley seems to suggest that the calculations which pre- cede this final interpretation are actually dispensible, but his works contain no positive assertion on this point. In the absence of such assertions I surmise that Berkeley would be inclined to square circles and draw tangents to curves entirely by gross visual estimation, assuming, as it seems, that the results would not visually differ from carefully drawn tangents that are produced after preliminary calculation in the differential calculus. I can find no evidence or suggestion for any other procedure in Berkeley. But my surmise seems to be well inkeeping with Berkeley's fundamental assumption that geometry, and likewise analysis, are empirical sciences that must ultimately subject them- selves to the judgments and estimates of the senses. In conclusion let me once again quote from the Philosophical Commentaries. Toward the end of the first part of that diary he writes: "The Mathematicians think there are insensible lines, about these they harangue, these cut in a point at all angles,.these are divisible ad infinitum. We Irish men can conceive no such lines."lll 44 111No. 393, lee Works of George Berkeley, V01- I-, p. . 110 And a little later "I Publish not this so much for any— thing else as to know whether' other men have the same 112 Ideas as we Irishmen." As it turned out, some other men had different ideas. 112m. 398., Ibiq. CHAPTER III PIERRE BAYLE My concern with Bayle in this chapter will be twofold: I wish to investigate Bayle's contribution to the philoso- phical discussion of the problem of the continuum and of infinite sets, and secondly I want to make some comments on the matter of Bayle's influence upon Berkeley. I have vio- lated the historical sequence by discussing Bayle after Berkeley, since it seemed more convenient to discuss Bayle's .influence after the material on Berkeley had already been assembled. Bayle‘s main work and the one for which he is best knaown is the Dictionaire,113 and I shall confine my discussion t<> views contained in it. The Dictionary does not set forth “filat one could call a philosophical system. Rather, it discusses philosophical topics only incidentally and in CNDrrnection with the biographies of the philosophers contained 113Pierre Bayle, Dictionaire historique et critique, RCDtrterdam 1697. This is a two volume edition. A greatly amended second edition in four volumes was published in 1702. 1“ 'the present paper, I shall quote Bayle after the second English edition of the DiCtionaigg, London 1734-38. The anno- tEi"tions will be made by citing the name of the article in gu‘fiisstion, and, if required, the letter and number of the note 1 . r1 (guestion. 112 in that work. Nevertheless, penetrating philosophical insight reveals itself in these occasional remarks, and a definite philosophical persuasion is quite apparent in them. The Dictionaire exercised considerable influence, and occupied a position of much greater importance in intellec- . . 114 tual history than is the usual share of reference works. I think that it is safe to assume that the magnitude of Bayle's influence was, in part, due to the fact that he entered the then topical dispute about the delineation of the boundaries of faith and reason with extraordinarily persuasive arguments, arguments that soon earned him the name of a sceptic. Bayle‘s philosophical persuasion with respect to these matters is, in a sense, a continuation of 114That the Qictionaire was widely used is shown by the fact that upon the investigation of 500 private libraries of the 18th century in France the work was found in 288. (See Selections from Bayle's Dictionary, ed. E. A. Beller and M. duP. Lee, Jr., Princeton 1952, p. XX). Forty-some years after his death, Berkeley's and his son's and grand- son's library was sold. According to Popkin, (Richard A. Popkin, "Berkeley and Pyrrhonism", The Review of Metaphysics, Vol. V., 1951-52, pp. 223-246) a copy of Bayle's Dictionaire was contained in that library. Popkin bases his assertion on the authority of A. A. Luce, (cf. Luce's edition of Berkeley's Philosophical Commentaries, London 1944, p. 388) who in turn trusted his own reading of an article by Aaron, Ming, N.S. XLI, p. 465 ff, which discusses the content of the library auctioned off. Aaron mentions only Boyle's, not Bayle's works as contained in Berkeley's library. That the Encyclopedists paid great heed to Bayle's opinions is well known, but it is obviously erroneous to assume that his ideas were propagated exclusively through that circle. 113 ‘ 1 that expressed in the Port Royal Logjc. In essence it is the denial of the possibility that a consistent descrip- tion of reality can ever be achieved. In the Port Royal_ Logic it had been asserted that "there are some things which are incomprehensible in their manner, yet certain in their existency, we cannot comprehend how they are, however it is certain, they are."116 and Bayle notes with approval that the Port Royalists had already pointed out that researches concerning the nature of the infinite have their only use in forcing the understanding "however unwilling, to own that some things exist though it is not capable of comprehending them... All the force of human understanding cannot compre- hend the smallest atom of matter, and is obliged to own that it clearly sees that such an atom is infinitely divisible, 117 without being able to see how that can be." This insufficiency of reason over against reality was supposed by Bayle as well as the Port Royal Logicians to lead the thinker to an unquestioning acceptance of the 115See Introduction to this dissertation, p. 1f. 116 (Antoine Arnauld), Logic or the Art of Thinking, p. 392. 117Bayle, pp. ci§., Article geno, End of remark G. Bayle took the quotation from the Port Royal Logic, loc. cit. 114‘ doctrines of religion, or at least to wrest from him the argument that these doctrines cannot be accepted because they are contrary to reason, since not even the description of physical reality can be carried out without finally lead- ing to inconsistencies. There is some doubt, however, whether or not Bayle was ultimately sincere with respect to the persuasion that I have delineated above: In the article Leucippus Bayle makes the following statement: Leucippus, Epicurus, and the other Atomists might have guarded against several unanswerable objections, if they had bethought themselves of giving a soul to every atom... I know they . could not have avoided all difficulties by ascribing it to them: they might still have been pressed with invincible objections. Yet there had been some glory in parrying a thrust here and there.118 ' This quotation is apt to substantiate to some extent the claim that I made above, namely that Bayle did not be- lieve that an ultimately consistent and trustworthy meta- physic or science could be developed. When sufficiently hard pressed, any position would lead to absurd consequences, so Bayle contended. Now part of the task of the Dictionaire clearly was to investigate various philosophical positions, 118 Ibid., Article_Leucippus, end of note E. 115 not in order to accept one or the other, but to show that in the final analysis they are all untrustworthy. I do not wish to decide here, and it is quite unnecessary for the purpose at hand to do so whether this undertaking was designed to show forth the limitations of reason and to support the position of faith, or whether it was performed for the glory that there is dealing many a thrust. Thus, while the over-all aim might have been to display’ brilliance in criticism or to demonstrate the weakness of reason for the benefit of faith, the result is that the Dictionaire hardly ever expounds or establishes a doctrine without criticising or demolishing it in some other passage or per- haps even some other volume of the work. As a case in point let us consider some arguments connected with naive realism and immaterialism as they occur in the Dictionaire. We find the following situation. In the article Anaxagoras, Bayle criticizes that philosopher who seemed to have assumed that the ultimate components of bodies are destructible. Bayle points out: Compound Bodies alone are born and die and pass through a thousand Vicissitudes of Genera- tion and Corruption; but Principles retain their Nature unchangeably under all the Forms which ‘are successively produced. Anaxagoras could not say this of HIS Principles. 119Ibid., Article Anaxagoras, Remark C, No. I. 116 and Wood, when destroyed by Fire, ceases not to exist as Matter, or extended Substance. Thus there is a great Defect in the System of Anaxagoras. A little later he criticizes Moreri for attributing a certain doctrine to Anaxagoras by exclaiming: Here is Earth, there Air and Water; here a Meadow, and there a Wood. Anaxagoras would have been more extravagant, than even the most absurd Visionary that was ever put in a Mad- House, had he entertained any Doubts about it.121 The point at issue was the opinion, which Moreri had attributed to Anaxagoras, that the universe is homo- geneous. So in the last quoted passage Bayle did not want to defend the existence of external matter. but the hetero— geneity of the universe. Nevertheless, the language is not that of a phenomenalist or immaterialist, but rather that of a realist, a position which was clearly expressed in the quotations preceding the last one, and which clearly underlies Bayle's criticism of Anaxagoras. Now the doctrine that is here used, or at least pre- supposed, does not tally in the least with the immaterialism that is proposed in the articles Pyrrho and Zeno. as we 120113161. 121 . Ibid., remark C, No. IX. 118 that bodies are coloured, and yet it is a mistake. I ask, whether God deceives men with respect to those colours? If he deceives them in that respect, what hinders but he may deceive them with respect to extension. This latter illusion will not be less innocent, nor less consistent. than the for- mer. with the most perfect being.121 And further on Bayle points out "God does not force you to say. that it does ex‘st, but only to judge that you . . . "122 feel It, and that It appears to you to eXist. While Bayle here merely puts in doubt the existence of external matter on the grounds that there is not a sufficient reason for believing it, he produces very force- ful reasons for denying its existence in the article Zeno. Before proceeding to a discussion of these arguments, let me again caution against the assumption that these dis- quisitions are intended to establish the foundations for an immaterialist or idealistic philosophy. They are only part in the general plan of «demonstrating the unten- ability of any system of metaphysics. Thus, while the existence of external matter is put in doubt in Pyrrho, and a demonstration against this existence is offered in Zeno, external matter is nonchalantly assumed in Anaxagoras, as 121Ibid., Article Pvrrho, remark B. 122Ibid. 117 shall presently see. It is clear, then, that Bayle's critical endeavours do not proceed from a well formulated and systematically developed philosophical position, but that they use whatever means are available, or can be pro- vided ad hoc, in order to demonstrate the untenability of any given philosophical system. It seems then that we cannot attribute to Bayle a philosophical position or sys- tem in the ordinary sense. but rather some sort of meta- position, which maintained the futility of any philosophical commitment. This explains. and perhaps was meant to excuse. the eclectic and inconsistent method of criticism found in the Dictionaire. But let me now try to document the phenomenological or immaterialist views that are set forth in the articles Pyrrho and gang. In Pyrrho the existence of external matter is put in doubt, and in ggng space and external matter are denied outright, and forthful reasons are presented in support of this denial. In Pyrrho, Bayle writes: I have...not one good proof for the existence of bodies. The only good proof they can give me for it, is, that God would deceive me, if he imprinted in my soul the ideas I have of body, if there were no bodies, but that proof is very weak; it proves too much. Ever since the beginning of the world all men, except, perhaps, one in two hundred millions, do firmly believe 119 we have seen. The demonstrations in g322_are not expressions of what Bayle affirms. but propositions which he contemplates. A peculiar feature of relation between Bayle and Berkeley now becomes apparent: if there was any influence of Bayle upon Berkeley. we cannot say that Berkeley was persuaded by Bayle's convictions, but rather, that Berkeley asserted some of the propositions which Bayle merely dis- cussed. Thus any discussion of the relation between these two men will have to acknowledge that, while Berkeley pro- bably accepted some of Bayle's demonstrations. he was con- vinced, unlike Baylethat a consistent and rational account of reality can be given. and that the tenets of religion. are not well served through attempts at demonstrating the fundamental irrationality of the world. How could Berkeley have come to such a position if the the_Dictionaire offered convincing arguments against every philosophical position which is discussed there? The answer is that the Dictionaire actually falls far short of achieving this goal. On one hand, there are very good arguments against the existence of external matter, but the immaterialism that is thus established is nowhere con- vincingly refuted. Rather. as in Anaxagoras. realism is assumed, but not proved to be tenable. 120 It must be noted that the position delineated in the articles Pyrrho and Zggg taken in itself does not con- stitute a philosophy that could properly be called sceptical. After all, the affirmation that there is no external matter is an affirmation. I believe that Bayle wanted to point out that there are very good arguments against naive realism, but that an immaterialist philosophy is not a good alternative. In fact. a decision between immaterialism and realism would either run counter to the arguments in Eggg. or contradict what everybody knows, namely that external matter "obviously" exists. Thus, no matter how we proceed. an inconsistency is immediately forthcoming. It is to Berkeley's credit to have realized for the first time that the one alternative. namely epistemological realism, is not really supported by any arguments, a fact that Bayle completely overlooked. This is one of the reasons why any assertion that Bayle anticipated Berkeley must be accepted with great reservations. I realize that the interpretation which I have here put on the passages in Bayle is not the customary one. Traditionally, the fictional personage who presents the above quoted passages in the article Pyrrholz3 is called 123See above, pp. 117f. 121 the Abbe Pyrrhonien, indicating what is here stated is Pyrrhonist or sceptical position. Popkin asserts that the argument expresses "a brilliant conception of the ultimate in scepticism."124 However. the viewpoint expounded by the Abbe Pyrrhonien is not a sceptical. but an immaterialist or, if you will, phenomenological one. Notice again the passage "God does not force you to say that it does exist, but only to judge that you feel it, and that it appears to you to exist."125 Again it is Berkeley's merit to have emphasized time and again against a welter of misunderstand- ing that the phenomenological vieWpoint must not be con- founded with the sceptical one, that they have nothing in common. It is, in a way, the most important point of his system. The arguments in gy££h2_can be used for the support of a sceptical philosophy only, if a naive realism is main- tained at the same time, and if the resulting inconsistency is turned into an argument for the whithholding of judgment. It is now time to turn to an examination of the arguments which Bayle brings forth in support of his 124Richard H. Popkin, "Pierre Bayle's Place in 17th Century Scepticism" in Pierre Bayle, Le Philosophe de Rotterdam, Paris 1959, pp. 1-19, p. 6. 1ZSSee above, p. 118. 122 "irrationalism". They are of two kinds. The arguments offered in Pvrrho point, in a rather naive way, to the so- called mysteries of religion, pointing out that the pro- positions put forth there are some of them contrary to all reason and should nevertheless be accepted. But in Pyrrho it is also suggested that extension is a secondary quality. If this assumption could be proved, i.e. if the external extended matter could be shown to be illusionary, then a contradiction with naive realism would arise. I think that in Bayle's opinion this would make both naive realism and phenomenalism doubtful, and would show that they are in no better position than the revelations of religion as far as plausibility is concerned. The argument for the non-exis- tence of external matter is presented in 2232- It is, as . we shall see, of the reductio ad absurdum type. Let me remark, in passing, that the employment of this type of argument is not in keeping with the general tenets of Bayle's undertaking: if the inconsistency of an assumption does not necessarily discredit it (see the assumptions of revealed religion), then reductio ad absurdum is of little value. Let us have a look at the argument. Bayle argues in support of Zeno's contention that there is no motion, and 123 he writes the following: There is no extension, therefore there is no motion. The consequence is good, for what has no extension fills no space, and what fills no space cannot possibly pass from one place to another, and consequently move. This is incon- testable; the difficulty is then to prove that there is no extension. Zeno might have argued thus: Extension cannot be composed either of mathematical points, or of atoms, or of parts divisible ad infinitum; therefore it's existence is impossible. The consequence seems certain, by reason it is impossible to conceive more than these three modes of composition in extension; wherefore the antecedent alone remains to be proved. A few words shall suffice as to mathe- matical points; for a man of meanest capacity may apprehend with the utmost evidence, if he is but a little attentive, that several nothingnesses of extension joined together will never make an extension...Wherefore...let us take it to be impossible, or at least inconceivable. that matter should be composed of them... Nor is it less impossible or inconceivable that it should be composed of Epicurean atoms, that is, of extended and indivisible corpuscles; for every extension, how small soever, hath a right and a left side, an upper and lower side: therefore it is a conjunction of distinct bodies; and I may deny of the right side what I affirm of the left, for these two sides are not in the same place: a body cannot be in two places at once and consequently every extension which fills several parts of space contains several bodies... whence it follows that if there be an extension, its parts are divisible in infinitum. But on the other side, if they cannot be divisible in infini- tum, we ought to conclude the existence of exten- sion impossible, or at least incomprehensible. An infinite number of parts of extension, each of which is extended, and distinct of all others, as well with respect to its entity as to the space which it fills, cannot be contained in a space one hundred thousand million times less than a 124 hundred thousands of a barley corn....If there be no body but what contains an infinity of parts, it is evident that each particular part of extension is separated from all others by an infinity of parts, and that the immediate contact of two parts is impossible, wherefore the existence of extension necessarily requiring the immediate contaCt of its parts, and that immediate contact being impossible in an exten- sion divisible in infinitum, it is evident that the existence of such an extension is impossible. 126 Of the three arguments here presented, only the case against Epicurean atoms holds water. They cannot be the ultimate constituents of extended bodies since they are themselves constituted of parts. But while Bayle argues, in the case of these atoms, against their ultimacy, in the other two cases it is the mode of composition which provides the difficulties. Now none of these latter argu- ments are cogent, at least not unless important qualifica- tions are added. In the first argument it was asserted that several points "joined together" will not make a finite extension. The difficulty seems to lie in the phrase "joined together". In the sequel we shall see that one of the most important advances in the analysis of continuous quantities was Bolzano's realization that an infinity of points, when "joined together" in a certain way, can 126Bayle, op. ci§., Article geno, Remark G. 125 constitute a finite (continuous) extension. I take Bayle's remark to mean that several points, no matter how many, when joined together, no matter in what way, will not make a finite extension. This statement is clearly false. Thus the argument against points is not valid. I presume that it is precisely the intuitive accompaniment of such a phrase as "joined together", or the mental image that goes with it, which misled Bayle as it did so many of his contemporaries. The argument against infinite divisibility is like- wise invalid. First, it is not the case that an infinite number of finitely extended parts of extension cannot be contained in a finite extension. If a half inch is added to an inch, and a quarter inch to the sum of the two etc., the total will not exceed two inches, even if infinitely many of these finitely extended lengths are added in accord- ance with the law of the series. To be sure, I cannot actually produce all these different lengths first, and then join them together; all I can do is to give the law ‘according to which they must be produced and joined, and I believe that it was this restriction which lead Bayle to believe that an infinity of finite extensions cannot be contained in some other finite extension. 126 Finally, it has been recognized for quite some time, that it does not make sense, given a point on a line, to speak of the "next" or neighborning point, as it also does not make sense, given a moment, to speak of the "next" moment. If two points are distinct, then there must be another point which lies between them, from which it follows that there must be an infinity of points which lie between them. I believe that this fact was first recognized and emphasized by Boscovich127 and later on accepted by Bolzano, as I shall show. Bayle apparently recognized this feature of continuous sets. but it seemed so incredible to him that he preferred to reject the notion that the con- tinuum is infinitely divisible. However. it must be noted that in the last argument given above the concept of exten— sion is arbitrarily restricted by the assertion that it requires the immediate contact of its parts. If, as seems to be the case, by these parts are meant the ultimate parts or points, then this requirement would in fact lead to the elimination of continua, or extension. since two points 127Ruggiero Guiseppe Boscovich. Theoria Philosophiae Naturalis, Vienna 1758, 8 30-33.' See Ernst Cassirer, Das EEkenntnisproblem, IBVOls. 3rd. ed., Berlin 1922, Vol. 2, P- SlOf. ' 127 that are in "immediate contact" are identical. It is there- fore this arbitrary restriction which must be rejected, and _may be rejected, since it can be shown that immediate con- tact of points is not necessary. or even possible. in the type of serial order which we call a continuum. We see then that Bayle's entire argument derives its superficial plausibility merely from the difficulties connected with continuous sets. and. generally. from the counterintuitive features of infinite sets. However, as may be expected. arguments of this sort were the rule rather than the exception at Bayle's time, and they exerted a tre- mendous influence upon philosophical speculation. It has been suggested that these discussions of Bayle's exercised considerable influence upon the develop- ment of Berkeley's philosophy, and it is this claim which I shall now examine.128 Popkin tries to rake together all the evidence that would support the supposition at issue. He points out that Berkeley's repeated and vigorous insistence that his 128Both Popkin and Luce have asserted that Bayle strongly influenced Berkeley. Cf} Richard H. Popkin, "Berkeley and Pyrrhonism", The Review of Metaphysics, Vol. V-, 1951-52, PP. 223-246 and A. A. Luce's note on p. 388 Of his editio diplomatica of Berkeley's Philosophical Commentaries, London 1944. ~128 philosophy is not a sceptical one can be interpreted as an attempt to distance himself from Bayle and the reputation that the latter had acquinal. He points out that Berkeley had obviously acquainted himself with some of the arguments in Zeno. since entry no. 358 of the Commentaries reads "Malebranche's and Bayle's arguments do not seem to prove against Space. but only Bodies."129 Considering the wide distribution and the popularity of the Dictionaire, and the material accumulated by Popkin, there seems little doubt that some influence took place, especially as regards the treatment of primary qualities. However. in their zeal for connecting Berkeley with Bayle. both Popkin and Luce have overlooked that there is a rather considerable dis- agreement between the two philosophers, especially as con- . . . . 130 cerns the topic of this dissertation. After having presented his case in the form quoted above, Bayle summarizes his results in the following fashion: All those who argue an extension are determined in their choice of an hypothesis no otherwise than by the following principle: I; there are but three ways of explaining_a subject, 129The Works Cf George Berkeley, V01- I. P- 43- 1301 have already pointed at another divergence concerning scepticism, above, pp. ll9f. 129 the truth of the third necessarily follows from the falsity of the other two. A zenonist might tell those who choose one of these three hypo— theses: you do not argue right, you make use .of a disjunctive syllogism...The fault of your argumentation lies not in the form, but in the matter: you ought to lay aside your disjunctive syllogism, and make use of this hypothetical one: If extension existed, it would be composed either of Mathematical points, or of Physical points, or of parts divisible in infinitum. But it is not composed either of Mathematical points, nor of Physical points. nor of parts divisible in infinitum. Therefore it doth not exist. Compare this with entry no. 26 of the Philosophical Commentaries, which says: "Infinite divisibility of exten- sion does suppose ye external existence of extension but the latter is false. ergo ye former also."132 Now Luce asserts that "entry no. 26...relates the infinite divisi- bility to external extension exactly as the Zeno article does;"133 and Popkin fully agrees with this result.134 However, a moments consideration will show that such is not at all the case. For one thing, the consequent in Bayle's hypothetical syllogism is an alternation of three members. l3lBayle, op. cit.. Article Zeno, remark G. q l‘2The Works of George Berkeley. Vol. I.. p. 10. 133A. A. Luce. loc. cit. 134 Richard H. Popkin, op cit., p. 243. 130 One could,however assume that Bayle listed all three possi- bilities only in order to serve the tenets of his encyclope— dic enterprise, and that the case against atoms was already so well established that Berkeley deemed their discussion superfluous. Furthermore. Berkeley might have realized that the infinite divisibility and constitution of points.amounts to the same thing: But even if one were to agree to all this. a fundamental difference would still remain. If we consider only the case of infinite divisibility. Bayle's argument would read: 'if extension exists, then it mustlxg infinitely divisible: But it is not infinitely divisible. Therefore it does not exist.‘ On the othe: hand. Berkeley's argument could be phrased thus: 'If something is infinitely divisible, then it exists externally. But nothing exists externally. therefore, nothing is infinitely divisible.‘ Thus, to claim that Berkeley relates infinite divisibility to external extension exactly as the Zeno article does is patently false. Rather. in Bayle the denial of external extension is the final result of the argument, in Berkeley it is a premise. Actually, Berkeley's argument is similar to the supporting proofs of Bayle's in which he attempts to demonstrate the impossibility of infinite division, but while Bayle‘s arguments suffer from logical inadequacies, 131 Berkeley puts forth a metaphysical assumption which in fact. if true. would remove the difficulties concerning the compo- sition of bodies, as I have shown above. The differences between the two arguments can be summed up as follows: the texminus ad guem of Bayle's demon- stration is the proposition that extension does not exist. In order to show this, a (fallacious) proof is offered to the effect that extension is not infinitely divisible. In Berkeley's argument. the proposition to be proved is that infinite division is impossible. To show this. it is assumed as a hypothesis (not proved) that there is no external extension. Thus, here again we must meet the claim that Berkeley was strongly influenced by Bayle with great reservations. Their arguments differ essentially as their aims were different. Berkeley was primarily concerned with the problems of the infinite, while Bayle's aim. at least in gppp_was to dis— credit naive epistemological realism. Nevertheless. it is a likely supposition that some influence took place. Let me conclude this chapter with another quotation from Bayle which tends to substantiate this latter assumption. Since the same bodies are sweet to some men 132 and bitter to others, it may reasonably be inferred that they are neither sweet nor bitter in their own nature, and absolutely speaking. The modern Philosophers, though they are no Sceptics, have so well apprehended the foundations of the epoch with relation to sounds, odours, heat, and cold, hardness and softness, ponderosity, and lightness, savours and colours etc. that they teach all these qualities are perceptions of our mind. and do not exist in the objects of our senses. Why should we not say the same thing of extension? If a being, void of colour, yet appears to us under a colour determined as to its species. figure and situation. why cannot a being, without any extension, be visible to us, under an appearance of determinate extension, shaped and situate in a certain manner?135 35 Bayle, op. cit., Article Zeno, Remark H. CHAPTER IV IMMANUEL KANT So far we have discussed three approaches to the problem of the composition of the continuu. and Kant was apparently familiar with all three of them. In the preface to the first edition of the Critique of Pure Reason he asserts that he has "found a way of guarding against errors which have hitherto set reason, in its non‘empirical employ— ment. at variance with itself"; and he continues: "I have not evaded its questions by pleading the insufficiency of human reason."136 The difficulties which set reason against itself are. of course. those which are recorded in the "antinomies". of which the second is of especial importance for our present investigation.137 It seems to me that the above quotation 136I shall quote from Norman Kemp Smith, A Translation of Kant's Critique of Pure Reason, London 1929, but, as cus- tomary. I shall give the pagination of the first (A) and second (B) editions of 1781 and 1787. All other works will be quoted after the Akademieausgabe, Berlin 1902 ff, but I shall consult and indicate already existing translations. The present quotation is from A 12. 137 , . . . The Second Antinomy (Critique of Pure Reason, A 434, B 462) is stated thusly: "Thesis: Every composite 134 indicates Kant's familiaritvaith earlier approaches such as Bayle's which blaime the arising of contradictions in specula- tion upon the insufficiency of human reason. According to a recent commentary. the problem of the constitution of matter and Bayle's account of the issue were frequently discussed in the Wolfian school. so that there is sufficient reason to suppose that Kant did not merely mean to attack a hypothetical position in the above quoted passage.138 But not only was Kant familiar with the school of thought that blamed the insufficiency of human reason for the arising of antinomies. he also seems to have known Berkeley quite well. However, it is doubtful that he envisaged Berkeley's philosophy as an attempt at solving or removing the problem of the constitution of (continuous) matter. He says of Berkeley: He (Berkeley) maintains that space. with all the things of which it is the inseparable condi- tion, is something which is in itself impossible; and he therefore regards the things in space as merely imaginary entities (Einbildungen) Dogmatic idealism is unavoidable. if space is interpreted substance in the world is made up of simple parts, and nothing anywhere exists save the simple or what is composed of the simple. Antithesis: No composite thing in the world is made up of simple parts. and there nowhere exists in the world anything simple." 138Cf. Gottfried Martin, Kant's MetaPhYSiCS and Theory of Science. Manchester 1955, p. 47. 135 as a propert that must belong to things in themselves." 39 If this passage is interpreted to say that Berkeley developed his philosophy because he recognized contradictions in the assumption of continuous bodies which fill space, then Kant recognized precisely the starting point of Berkeley's philosophy. I have some doubts about this. Nevertheless, Kant here, in a more or less vague fashion. seems to link Berkeley's problem with that of the second antinomy. That Kant was familiar with Leibniz is commonplace and does not need much further substantiation. Kant was an avid student of Leibniz and began his philosophical career entirely within the tradition of the Leibniz-Wolff school. The problem of the composition of the continuum was much discussed in these circles and several of Kant's first philosophical essays concern themselves directly or indir- ectly with it. Thus it is clear that Kant, in addressing himself to the problems of the second antinomy. consciously became part of a long line of attempts at a solution of this l39Critique of Pure Reason. B 274. 136 problem.140 What distinguishes Kant from some of his predecessors. notably Bayle and the Port Royalists. and from many of his successors, is a wholesome fear of contiadictions. Time and again he declares that one of the most important features of his Critical Philosophy is the avoidance of antinomies that have hitherto bedevilled speculation. Thus in the preface to the first edition of the gritique of Pure Reason he bemoans the fact that through the uncritical acceptance of "principles which overstep all possible empirical employment... human reason precipitates itself into darkness and contradic- "141 tions. The Critique, of course, is to be the cure for this malady. In the preface to the second edition he makes 142 a similar point, and the body of the work contains many related remarks. Finally. an explicit statement of the 140According to Erich Adickes, Kant als Naturforscher. 2 Vols., Berlin 1924/25, Vol. I, p. 172, Kant in the Monadolo- gia Physica, Akademieausgabe. Vol. I. pp. 473-487. asks him- self the question, "what is it that makes it happen that matter, stuff, occupies a space and cannot be removed from that space?" Adickes claims that it was Kant's "immeasurable merit" to have seen "the necessity for that question." On the evidence of our previously collected material it is evident that to claim originality for Kant on that score is patently absurd. 141Critique of Pure Reason, A VIII. 142Ibid., B xx. 137 difficulties and contradictions which beset reason in its 143 "uncritical" use is found in the Antinomies. In the second half of the last century the importance of the Antinomies for the development of Kant's philosophy came to be realized. Alois Riehl. for one. pointed out that the essential features of Kant's philosophy sprang from the desire to avoid the occuiience of the antinomies. and Erdmann. Vaihinger, Adickes and many others accepted his opinion. so that now it is the subject of scarcely any' further dispute.144 Thus I cannot claim any originality in elaborating this point again. Nevertheless, several reasons prompted me to include a consideration of Kant in the piesent disserta- tion. One is that previous commentators have ielied largely on testimony contained in letters and posthumously found notes in order to establish the importance of the problem of the antinomies for Kant's philosophy, i.e. they have chosen a historical approach. I shall confine myself to a discussion of his published work in order to establish the same point. 4 1 3Ibid., A 407-567. B 435-595. 144Cf. Klaus Reich in the introduction of his edition of Immanuel Kant, De mundi sensibilis atgue intelligibilis forma et principiis. Hamburg (Meinei) 1958, pp. VIII ff 138 This procedure will have the advantage of making clear the inner-systematic importance of the problem of the antinomies. in particular the second antinomy, and will thus differ markedly from a mere ascertainment of historical sequence A second reason why I thought it necessary to include a discussion of Kant lies in the fact that many commentators. particularly Riehl. do not seem to have been aware at all of the implications oftha paoblem at hand. Thus Riehl feels justified in claiming that "opposite assertions, based on entirely different presuppositions. do not contradict one anothei".145 and that the proofs for and against the infinite divisi- bility of matter are not conducted from the same or similar standpoints. The reasons offered on either side are not homogenious, so that there can be no real contradiction between them. The thesis is proved ongologically from the conception of a composite reality. while the antithesis is proved for perception from the idea of space 146 Now clearly, for the occurrence of a contradiction it can be of no importance whateverlxwveach of the contradictory statements has first been established. Nor did Kant doubt for a moment that he had contradictions on his hands, merely 145Alois Riehl, Introduction to the Theory of Science and Metaphysics, London 1894, p. 270. 146 _ Ibid., p. 271. 139 because thesis and antithesis had been established in different ways. But Riehl committed another major blunder. With reference to the third and fourth antinomy he points out: In order to understand the proof of the theses of these dynamical antinomies, it is necessary first to forget the doctrines es- tablished by Kant in the Transcendental Analytic. This evident contradiction in Kant's system (gig) can only be explained by assuming that the antinomies are the oldest part of the Critique, or rather that they preceded it.147 There could be no clearer testimony that Riehl‘s interest and ability were merely historical. not systematic. The passage shows a misunderstanding of the position of the antinomies in Kant's system while, at the same time, it establishes a historical thesis that is probably correct. It was Kant's precise objective first to establish in each antinomy both the thesis and the antithesis from a pre- critical viewpoint. i.e. forgetting the doctrines established in the Transcendental Analytic. and then to discuss and remove the ensuing difficulties by bringing to bear on them the findings of the preceding parts of Critique. i.e. the Transcendental Esthetic and Analytic. On the other hand, there is a good deal of historical testimony to vindicate 147Ibid. 140 Riehl‘s thesis that the antinomies (possibly even in their final form) preceded much of the rest of the Critique.148 I find it generally the case that commentators either did not pay much attention to the systematic significance of the antinomies for the rest of the critical enterprise,149 or else were determined largely by historical considerations and preoccupied with the establishment of such philological theses as the so—called patchwork theory. according to which the CJitique of Pure Reason was pieced together out of a large number of preexisting writings.150 It is for all these reasons that I propose to investi— gate again the importance of the antinomies, in particular the second one. for the development and character of Kant‘s 148A letter from Kant to Garve has been found dated the let of September, 1798, in which Kant says, "It was not the investigation as to the existence of God, but the anti- nomies of pure reason which first wakened me from a dogmatic slumber, and impelled me to a critique of reason itself." Cf. also the grolegomena, beginning of § 50. Akademieausgabe. Vol. IV, p. 338. 149E.g. Norman Kem Smith, A Commentary on Kant's Critique of Pure Reason, : New York 1950, and T. W. Weldon, Kant's Critique of Pure Reason, é Oxford 1958. 150Cf. Alois Riehl, Der philosophische Kritizismus und seine Bedeutung_fur diGngSithe Wissenschaft. 3 Vols., Leipzig 1876-87, The above quoted work, Introduction to the Theory of Science and Metaphysiq§_(above p. 115) is a trans- lation of the third volume of yer philosophische Kritizismus. -fihe charge of preoccupation with historical and philological 141 . 151 philosophy. Before I proceed to analyze Kant's theories in detail. let me try to indicate briefly the epistemological status that Kant ascribed to his proposed solutions. It will be remembered that Berkeley described the main facet of his philosophy as the immaterial hypéthesis. In keeping with this characterization. supporting arguments were sought, as we have seen, not in propositions of which the immaterial hypothesis is a consequence, but in propositions which it entails. In opposition to this procedure. Leibniz delivers his system as a priori certain, and does not ordinarily attribute hypothetical character to it. How did Kant regard his own doctrines? In the preface to the second edition of the Critique of Pure Reason, when describing in a preliminary way his "Copernican revolution" with the aid of which certain contradictions can be avoided, questions can be levelled even against Vaihinger, whose commentary is generally held to be above reproach. Hans Vaihinger, Kommentar zu Kant, 2 vols. End. ed. Stuttgart 1922. It must be said, in vindication of Vaihinger that his commentary does not proceed beyond the Transcendental Esthetic, and that he discusses our present problem in an avowedly historically oriented Excurgz "The Historical Origin of the Kantian Doctrine of Space and Time", Vol. II, p. 422ff which follows the systematic exposition of the Transcendental Esthetics. 1511 have found the best discussion of the importance of the antinomies in Kant in Gottfried Martin, Kant's Meta— physics and Theory of Science, Manchester 1955. 142 he points out, The (Newtonian attraction) would have remained forever undiscovered if Copernicus had not dared, in a manner repugnant to common sense, (wider- sinnisch) but yet true, to seek the observed move- ments not in the heavenly bodies, but in the spectator. The change in point of view, analogous to this hypothesis, which is expounded in the Critique, I put forward in this preface as an hypothesis only, in order to draw attention to the character of these first attempts at such a change, which are always hypothetical. But in the Critique it will be proved apodeictically not hypothetically, from the nature of our repre- sentations of space and time and from the ele- mentary concepts of the understanding.152 It seems that Kant considered the introduction of a proposition as a hypothesis merely as a preliminary matter. and that any hypothesis, in order to be permanently acceptable must be "proved". In this respect his outlook did not change from his early rationalist days to the time of the Critiques. In one of his earliest writings, the Monadologia Physica, he criticizes those approaches to natural philosophy which do not accept any information but What is immediatelyi evident through experiment. He says: “Ex hac sane via leqes naturae exponere profecto possumus, legum originem et causas non possumus."153 Thus. through observation and experiments 152Critique of Pure Reason, B XXIII. 153Meta2h¥§jg§ cum geometriae iunctae usus in philoso- phia naturali, cuius specimen I continet monadologiam physicam, Konigsberg 1756, Akademieausgabe Vol. I, pp. 473-487, p. 475. 143 laws can indeed be made evident, but their origin and causes cannot be found in this way. This seems to be an invitation to speculation, to the formation of hypotheses which would explain the laws found through experimentation - a perfectly legitimate enterprise. However, the body of the Monadologia supposedly proves every hypothesis which is introduced there. Needless to say, many of these proofs are invalid. but the attempt is there. just as in the Critique of Pure Reason The difference between Kant and Berkeley could not be more striking. I am quite convinced that Berkeley did not think his hypothesis demonstrable in the same sense in which Kant sought to prove his. The immaterial hypothesis is said to be as good as its explanatory merit. Kant on the other hand. always thought of his doctrines as requiring some sort of deductive proof, or. to put it more strongly. he attempted to. and presumably believed that he did, prove all_proposi- tions which he offered. Interestingly enough, it is those parts of the Critique of Pure Reason which offer these proofs, namely the Esthetic and Analytic, which must be considered dated’although even they command interest at every turn. In offering a reconstruction of parts of Kant's philosophy I shall do some violence to Kant's own intentions by neglecting. for the most part, the alleged proofs that he 144 offers in support of his positions - otherwise I would have to discuss the entire Transcendental Esthetic and Analytic, a task much too formidable for the small scope of this paper. Thus I shall discuss certain of his propositions as though they had been intended merely to function as hypotheses, The above considerations point to a remarkable and perhaps fundamental distinction between the British empiri- cist school and the continental rationalism and idealism. Concerning the epistemological status of his doctrines, Kant did not differ at all from his rationalist predecessors. The earliest work in which Kant attempted to offer a reasonable solution to the problem of the constitution of matter was his Monadologia Physica. To understand fully the problem as it was envisaged in that little essay, let us first turn to a much later work, namely the grolegomena to Any Future Metaphysics. Here Kant writes: It will always remain a noteworthy phenomenon in the history of philosophy that there was a time when even mathematicians, who were at the same time philosophers, began to doubt. though not the correctness of geometrical theorems as far as they concern mere space, but at least the objective validity (Gflltiqkeit) and application of this concept to nature, since they feared that a line in nature might consist of physical points, hence the true space in the object consist of simple parts, although the space which the geometrician has in mind cannot possible consist of them.154 154Akademieausgabe, Vol. IV, pp. 253-383.§13, Note I. p. 287f. ' 145 It is quite clear that the object of this criticism is Christian Wolff, who was a mathematician and at the same time a philosopher. ’Wolff had assumed that the physical world consists of bodies which are extended, and which are made up of simple elements called 'atomi naturae‘ and some- times also 'monads'. Wolff seems to have subscribed to Leibniz' views that whatever is extended in space, and hence composite, must consist of simple, indivisible elements. But while Leibniz categorically denies the spatiality of these simple elements, Wolff was not quite certain what character he should ascribe to them. He believed that his atoms could combine to produce larger extended bodies, which he believed to be continuous, but since he could not explain the nature of this composition, he claimed that human notions of the composition of matter must remain unclear. However, in one way or another, a finite number of atoms was believed to produce a body of perceptible size, and hence it was concluded that the atoms must themselves have a finite extension. Hence any piece of matter could be divided down to the atoms, but not further. Geometrical space, on the other hand, was said to be infinitely divisible, hence, so it was argued, can have no simple parts. These considerations led Wolff to distinguish 146 between physical or natural Space (i.e. space occupied by a bodyL and geometrical or pure space.155 It is this distinction between two kinds of space that Kant has in mind when he claims that geometry and metaphysics are at variance, or at least were before his critical system. Once one realizes this distinction, and sees that geometry and metaphysics were thought to make con- flicting assertions about space, one understands the urgency of the Kantian question 'How is it that geometry can apply to experience?‘ which, of course, means the same as ‘How is it that geometry can be used in physical space when supposedly it describes accurately only its own special kind of space?’ For Kant, the puzzlement consisted in the fact that the application of geometry was successful despite the conflict between the metaphysical and geometrical description of (occupied) space — for, that there was but one space, and that Wolffs distinction was untenable, Kant assumed from the beginning. 1 This is a preliminary discussion of the problems that Kant attempted to solve in the Monadologia Physica. The 155Cf° Ueberweg, Grundriss der Geschichte der Bhilosophie, 3 V018,, Berlin 1905-1909, VOl. III, p. 228. 147 title of the little work already suggests its aim: £2327 physicae cum geometriae iunctae usus in philosophia naturali specimen. Both geometry and metaphysics are to be used jointly in natural philosophy. This means that on one hand the 'metaphysical' demonstration of the existence of simple bodies is accepted, while on the other hand the geometrical demon- stration of the infinite divisibility of space is also granted, even if that space is occupied by a body. First the term "monad" is introduced by definition: "Substantia simplex, NOD18 dicta, est guae non constat 156 pluhalitateypartium, guirum ura absque aliis existere pptest." Then a theorem is offexed, namely "Corpora constant monadibus".157 This is to be proved by the statement that if all composition were suspended, then the remaining parts obviously do not have composition, and hence are simple. This alleged proof is similar to one which was time and again offered by Leibniz. Its difficulty lies in the notion of 'suspending composition‘. I'am not at all clear what could be meant by this, and I cannot see that this "proof" demonstrates in any way the existence of ultimate parts. 156Akademieausgabe, Vol. I, p. 477. 157Ibid. 148 After thus having satisfied himself that there are ultimate parts to bodies - and Kant means finitely extended ultimate parts, as we shall see - he gives a demonstration that the space which a body occupies is infinitely divisible, and hence does not consist of simple parts: "Spatium, guod coxpora implent, est in infinitum divisibile, neque igitur l constat partibusgpgimitivis atqpe simplicibus." He offers the following pioof: Conside. a line ef159 of "indefinite" length, i.e. one that can be extended at will, and let it be filled with monads. (linea partibus materiae primitivis conflata) Call such lines "physical lines". On §£_draw at right angles another physical line ggJ and likewise at right angles to §£_another physical line ax; of the same length as 9g and different from 9g, Now mark points on 3f, call them g, h, i, k, etc. and connect these points through physical lines with c. 1581bid., p. 478. 159Notice that 'e' and 'f' do not denote points, but this is of no consequence for the proof. See diagram. 149 The point in which gg_inte1sects §b_is called 0. Now any line which is drawn from a point to the right of g to c will intersect gb_above<>, and as we choose points farther and farther to the right on ef, the intersections approach a more and more closely. In fact, Kant concluded, since we can ex- tend gf_at will, we can make as many divisions in §9_as we wish. According to Kant, this proves that §g_and hence space is infinitely divisible, and hence cannot consist of simple parts. As far as the mathematics of the situation is concerned, 'me proof did not offer any novelty, and Kant admits as much. Why then did he include it? The only innovation that it incorporates is the stipulation that the lines be "physical" lines, 1 e. filled with monads. Now it must be understood that the number of monads in any physical body is always considered finite, hence that a monad occupies a finite space (We shall see later on what it means for a body to be "filled" with monads). Cleaaly, this innovation makes the proof invalid, since the lines drawn between c and the points on §f_have finite width, so that only a certain number of them can be accomodated in the proximity of c. Kant apparently did not realize this. It is clear that the proof was to demonstrate something 150 over and above the similar geometrical proof, and while in fact it proves nothing, we can nevertheless inquire what it was supposed to prove. This is actually a quite simple matter. If a certain finite number of monads were located on abJ then for any monad m there is always a point n on g: such that gg_cuts through m. Or, to put it geometrically, for any finite part il_of §b_there is a point n on e; such that the intersection of gn_and ab_lies between i and j. This is supposed to show that the space which a monad occupies is always divisible, although the monad itself is simple. Or to put it otherwise: simple, finitely extended monads are located in a space which is infinitely divisible, although the monads themselves are not. Clearly, the demonstration is directed against Wolff, Who claimed that the space occupied by an indivisible body is itself indivisible, and who was therefore forced to intro- duce a distinction between geometrical and physical space. This situation is completely misunderstood by Adickes, who writes: Only the space which they (the monads) occupy is divided to infinity. Of the monads, on the other hand, only a finite numbe is present. However, if this is the case, then there is no reason why the monads had to be dragged into the proofs of the infinite divisiblity of space. 159Adickes, op. cit., Vol. I, p. 135. 151 That there was a yeason for considering the monads in this proof is indicated by the passage cited from the Prolegomena, in which Kant attacks the view that "the true space of the object" consists of simple parts. The demon- stration therefore must have been intended not only to show that space is infinitely divisible, but that it is so divi- sible no matter whether it is occupied by a monad or noto Thus, the distinction between physical and geometrical space is abandoned. But this distinction had served a purpose. If the space which a physical object occupied could not be divided beyond the smallest parts of this object, then, it was assumed, it did not make any sense to speak of matter as being divisible beyond its atoms. Infinite divisibility was restricted to geometrical space, which was considered a merely ideal construct. designed to satisfy the postulates of geometry In disregarding this attempt at solving the problem of the constitution of matter, Kant at once faced again the old problems that had been encountered, for example by Cordemoy. Let us see how these problems are dealt with. Consider theorem IV of the Monadologia Physica. It states "Compositum in infinitlm divisibile non constat Bartibus p.1mitivis s. simplicilus_"160 This, we know now, 160Akademieausgabe, Vol. I, p. 479. 152 needs the qualification that an infinitely divisible compound does not consist of extended primitive parts. But theorem IV gives rise to the corollary that if something does consist of simple parts. then it is not infinitely divisible; accord- ing to Proposition II, this holds of all bodies: "Corollarium: Corpus igitur quodlibet definito constat elementorum simplicium numero,"161 from which Kant concludes in Proposi- tion V that the monad not only is in_space. but occupies space. i.e. is extended. in spite of its postulated sim- plicity.162 Here then arises the old predicament of atomism. If the monad, or the atom. as case may be, is extended, how can it be called simple. Or, in other w0rds. how can a body be extended, but nevertheless indivisible? Adickes has leveled the charge against Kant that he confused physical divisibility with spatial extension. This charge must be investigated; it will serve to bring the difficulties of the atomist position into clearer focus. From these considerations it will be seen first. that the problem is 153 not nearly as simple as Adickes seems to have supposed. and second that Kant is not guilty of any confusion in this matter. Indeed. it will be shown that the second part of the Monadologia Physica was. in fact. designed to cope with the difficulties that arise from a distinction between exten- sion and "physical divisibility". We can best reach clarity about this matter by con- sidering the various meanings of the term ‘divisible'. In $0 to It in to doing I shall not investigate the difficulties that attach this term insofar as it is a "dispositional predicate". would be presumptuous to attack such a difficult problem this context. Also. the term will be understood as having do with division into spatial parts. Three meanings of 'divisible' can then be distinguished; namely. 1. x is divisiblel= Df. a law of the form 'if such and such is done to x, then x will fall into parts' is known. 2. x is divisiblezz Df. a law of the form ‘if such and such is done to x. then x will fall into parts' is not self-contradictory.. x is divisib1e3= Df. x occupies a finite space. This third kind of divisibility should actually be attributed only to geometrical objects. Here it is no longer a question of "taking something apart". One speaks of lines as being bisected i.e. divided by other lines. surfaces by lines etc. We may say that one line is divided by another line if the 154 two have a point in common. but both also have at least one point which they do not share. Thus. in this third sense of'divisiblefi,ve may say that a line or a surface or body is divisible3 if it consists of more than one point, i.e. if it is extended. Now since we are talking about division in space, I should think that if a body is divisiblel, then it is divisiblez, and if it is divisiblez. then it is divisible3. However. both Descartes and Leibniz, as well as many others believed that not only does divisibilityz imply divisibility3. but that the converse also holds. An assertion frequently found in these authors is one to the effect that an object which is extended in space is also "divisible. at least in thought". that is to say. if x is extended in space. than a law of the form "if such and such is-done to x. then x will fall into parts" is not self-contradictory. This then is the perennial pJedicament of the classical atomists: they must show that divisibility3 does not imply divisibilityz. In fact, to be an atomist in the classical sense is to defend precisely this point. But atomists have not generally rested with the assertion that there are finitely extended particles of matter which are nevertheless so indivisible. They usually took it upon themselves to describe these parti- cles in such a way that their view would become intuitively 155 plausible, a task from which they might better have refrained. Thus they attached pseudo—phenomenal properties to their atoms: Cordemoy called his "infinitely hard". Lambert called his "solid", and Gassendi topped Lambert by ascribing "absolute solidity" to his atoms. Now none of these attri- butions can be said to add anything to the respective author's central thesis that there are extended, but indivi- sible2 particles of matter. On the contrary. these embellish- ments were apt to cloud the issue. Leibniz for one did not think that the properties of infinite hardness or absolute solidity made it impossible to divide an atom "in thought", and he seems to have realized that the ascription of these properties did not add any force to, or make more plausible, the proofs which were offered for the existence of atoms in the first place. Kant comes up against similar difficulties. He had inferred. as we saw. that space is infinitely divisible,and therefore does not consist of simple parts. Matter, it is assumed, gges consist of simple parts, and therefore is not infinitely divisible. Hence the physical monads are said to ,"occupy" finite spaces: Kant speaks of the "space of the monad's presence". But if a monad occupies a finite space, why is it not divisiblez? Kant makes a rather clever sugges- 156 tion by which the monad "occupies" a finite space in a certain sense. without thereby becoming divisiblez. He contends that the monad proper is indeed unextended. but that it is enveloped in a field of forces which do not allow other monads to approach beyond a certain limit. "Monas spatiolum presentiae suae definit non plu alitate partium suarum substantialumL‘sed sphera activitatis, qua externas utrinque sibi praesentes arcet ab ulteriori ad se invicem appropinqua- tione."163 That is to say the monad does not "define" (circumscribe) the space of its presence through a plurality of its substantial parts. but through a sphere of "activity" which keeps the other monads from closer approach. Proposition VII cautions that the radius of this sphere of activity must not be confounded with the radius of 164 the monad propero The monad proper is altogether unex- tended. The force which Kant introduced. and which keeps monads from approaching one another beyond a certain limit is said to be the same force that others have called impene- trability.165 163gprg , p. 480. 1641b1g,, p. 481. 165Cf. prop. VIII. ibid., p. 482. 157 Thus the notion of impenetrability or repelling force be- comes crucial. This force guarantees that any given piece of matter is constituted of a finite set of monads, while allowing the monads themselves to be unextended. Thus, thew monad "occupies" a space not by being literally present in it, but by exercising a force in it. The repelling force which belongs to each monad is not considered constant within a certain sphere but is thought to decrease inversely proportional to the cube of the distance from the monad proper. In close proximity to the monad itself it is said to become infinite. Much later, in the Metaphysische Anfangsgrfihde der Naturwissenschaft, Kant makes it clear166 -- and in this respect his views did not change -— that he thought of the impenetra- bility of matter as what he calls "relative" impenetrability. That is to say matter, and thus also the monads are capable of being compressed to some extent. But since the repelling force increases toward infinity in close proximity of the monad proper, a total compression is assumed to be impossible. In the Anfangsgrgnde he contrasts "relative" impenetrability with "absolute" impenetrability, i.e. with the rigid 166Akademieausgabe, Vol. IV, pp. 465—565, p. 502. 158 occupation of space. A theory under which a space is filled with absolutely impenetrable matter he calls a theory of mathematical occupation of space, his own he calls a dynami- cal theory. The scheme presented in the Monadologia seems to work out quite well. -The monad proper is not extended and there- fore not divisiblez. But it nevertheless occupies space. Hence the desired result is achieved. But let us return again for a moment to the Anfangs- grflhde. While Kant's views had undergone considerable change between the Monadologia and this later work -- the Critique of Pure Reason falls between the two -- there is much pro- cedural similarity between the two. A passage from the Anfangsgrghde is helpful in explaining how Kant thought this kind of speculation to be justified. It seems that the desired results are achieved ultimately by way of definition. Thus, the system is developed in such a way that any critic . » eventually runs afoul of a definition. In the Anfangsgrunde Kant makes the following point: Lambert and others called that property by virtue of which it (matter) occupies space 'soliditY' (quite an ambiguous expression) and wanted it assumed for everything that exists (substance), at least as far as the world of outer awareness is concerned. According to their notions, the presence of something real in space should carry this resistance with it by virtue of its concept, hence 159 by virtue of the law of contradiction, and should thus bring it about that nothing can be co-present with such a thing in the same space. However, the law of contradiction does not repel a piece of matter which approaches to occupy a certain space in which another is found. Only when I attribute to that which occupies space a force of repelling any mobile matter which approaches can I understand how there is a contradiction in (assuming) that a thing penetrates into a space occupied by another thing, 67 ‘ It is patent that the attribution of force is no more successful in making impenetrability plausible, than is the attribution of solidity. In the final analysis, impenetra- bility is postulated in both cases, or, to put it otherwise: the atom, matter, or monad, as case may be are defined in such a way that the assumption of something else that occupies the same space with that atom, that monad or that piece of matter is contradictory, and it makes no difference whether the notion of force or that of solidity is called in to make the case plausible. Essentially, the situation is no different in the Monadologia. Here, too, it is the postulated properties of physical monads that would make it contradictory to assume that a monad is divisiblez, and it would seem that Kant has overcome a major difficulty of atomism by postulating such 167 . Ibid., p. 497. 160 properties for his monads as would make them "occupy" -- in a rather Pickwickian sense, to be sure -- a finite space, while they are nevertheless indivisiblez. Aside from impenetrability or repelling force, Kant later on postulates a further property of monads: another force is introduced, namelygravitation, which is said to pull the monads together.168 As with impenetrability, Kant also assigns a definite intensity to gravitation: it is said to decrease inversely proportional to the square of the distance. I cannot under- stand the reasons that led Kant to settle on the cube of the distance for repulsion, and the square in this case, but the following results from them:169 If the repulsion has a force of, say, 1000 units of one kind or another at distance 1 from the monad proper, and attraction the force of 100, then at distance 2, repulsion drops to 125, and attraction to 25. At distance 10, the respectiVe forces balance one another, and this distance then describes the limit of the"sphere of activity” of the monad. Adickes points out that Kant's spheres of activity 168Proposition X, Akademieausgabe, Vol. I, p. 483. 169 Cf. Adickes, o . cit., p. 175. 161 are literally spheres, in the sense that the monads cannot come any closer to one another than is permitted by the cir- cumference of these spherical entities, but that they also cannot stay any further apart.170 He finds some difficulty in the fact that Kant did not want to tolerate "empty spaces" 171 On this Adickes comments: "difficulties within a body. arise from the fact that his monads all have the same spherical volume. If they touch one another with this, small empty spaces must form in which the forces of repulsion do not have the preponderance."172 However, I fail to see why these small spaces deserve to be called empty. They can be no more nor less empty than the spaces included ig_the ideal spheres. Kant nowhere suggests that for a monad to occupy space its repelling forces must outweigh the attractive ones, Rather, he has developed a theory according to which matter consists indeed of monads which are loosely scattered in space, which are themselves unextended and hence indivisible, but which have extended areas of activity and thereby "fill“ space. To say that monads fill a given space here merely 1 70 id., p. 161. 171 Cf. proposition VIII, ibid., p. 482. 172 Ibid. 162 means that the forces of attraction and repulsion of the monads have values higher than some given value for any point in that space. The value can be set in such a way that the "pockets" between the spheres can.be considered filled. This then is Kant's first attempt at a solution of the problem of the composition of matter. The position he takes here is frequently called one of dynamism as opposed to atomism, but this distinction appears to me to be rather artificial. I prefer to think of Kant's essay as an attempt to describe atoms as both extended and indivisiblez. This way of looking at Kant's Monadologia Physica shows very clearly that he was not guilty of confounding spatial exten- sion and what Adickes call "physical divisibility". The entire problem of the Monadologia arises from this distinc- tion, as I hope to have shown. Kant's attempt is highly noteworthy, and finds its. place in this dissertation as an attempt at reviving atomism. But what is the significance of the Monadologia physica in relation to the problem of the composition of the con- tinuum itself? It seems that the little work constitutes neither an advance, nor a regression in this respect. The problem is not even considered. I believe that Kant was completely unaware of, or did not recognize, the difficulties 163 concerning the continuum of abstract space itself; and this in spite of his familiarity with Leibniz. He does not at this point betray any knowledge of the paradox of Galileo, nor of the fact that between any two points in a continuum there is another point. both of which were known and pro- vided considerable conceptual difficulties for some thinkers of that age. Kant nowhere shows any apprehension when he asserts that any finite space is infinitely divisible, nor does he seem to realize the implications of that stand. Rather. here as later on, he adheres to a definition of continuity that is clearly inadequate. but which in Kant never becomes the subject of any enquiry. This definition is "A quantum is continuous which is not composed of simples."173 Many of the views espoused in the monadologia physica Kant ’ never altered in his later years. despite the profundity of the change of his views from his precritical to his critical period. However, this does not mean that the stand l731h this form the definition is found in Kant's inaugural dissertation De mundi sensibilis atque intelligi— bilis forma etgprincipiis, Akademieausgabe. Vol. II, pp. 385-419. § 14.4, p. 399. The translation is taken from John Handyside: Kant's Inaugural Dissertation and Early Writings on Space, Chicago 1929, p. 540 I shall use Handyside's translation throughout the discussion of Kant's dissertation. Actually, the above definition does not occur in the Monadologia Physica. Instead a Weaker statement is introduced: Compositum in infinitum divisibile non constat partibus primitivis s. simplicius. (Akademieausgabe, Vol. I, p. 479. 164 taken in the Monadologia remained unproblematic to him. This early piece poses a number of problems which urgently demand resolution. The most outstanding of these is that matter as described in the Monadologia is not the same as it appears to the senses - it is a congeries of monads and their forces. while it appears, so Kant would hold. as continuous. I do not think that Kant was very much disconcerted by this fact when he wrote the Monadologia. The custom to regard all sensory experience as confused was too well entrenched among rationalists. I believe that it was Kant's encounter with Hume that forced upon him the recognition that the testimony of the senses cannot profittbly be discounted in all cases when epistemological or metaphysical problems arise. Thus Hume's influence made him recognize the pro- blematic aspects of his earlier views. The matter of Hume's influence upon Kant has often been discussed. and Kant frequently acknowledges his indebted— ness to Hume, especially in the introduction to the Prolego- mena, This seems to be at variance with the views that I have stated above. namely that the cosmological antinomies were the most important factor in the development of Kant's , 174 later philosophy. 174The problem here is not Hume's influence upon Kant 165 Unfortunately. the historical evidence on this point is not sufficient to decide the case. Kant sometimes attributes the awakening from his "dogmatic slumber" to his encounter with Hume. and at other times to the antinomies. What I wish to establish now is that the cosmological anti- omies would not have arisen. had it not been for Kant's acquaintance with Hume. The point is that the antinomies do not seem to have been recognized befoze. As long as experi- ence as a source of evidence is eschewed, the antithesis to both cosmological antinomies cannot be established. In the Monadologia we find a geometry which demands only a continuous space, and a metaphysics which demands finitely extended ultimate constituents of matter, but no evidence is recognized which would demand that the same matter for which metaphysics entails a finite number of constituents. should also have an infinite number of ultimate parts. Now if it was Hume who taught Kant the principles of empiricism, then it was also Hume who made Kant recognize the problem of the antinomies. Thus the dispute between Paulsen and Riehl toward the end of as far as the latter's analysis of causality is concerned. Influence in this respect is well nigh undeniable. Rather, the point at issue is whether or not Kant's first writing of his critical period. the Dissertation, which is not concerned with an analysis of causality, is also partially indebted to Hume. 166 the last century, whether it was Hume or the antinomies which prompted the development of the critical vieWpoint is rather pointless.175 Let us consider now how Kant's encounter with empiri- cism could have led him to recognize certain problematic aspects of his earlier philosophy. After the encounter with Hume's philosophy, Kant no longer discounts sensory experience lightly, but on the other hand, Hume's influence did not reach deep enough to make him discard the rationalist scheme advanced in the Monadologia. If such a half-way position is taken, an account must be made of the discrepancy between the rationalist account of matter on one hand. and the sensory experience of matter on the other._ Here lies the first problem. A second one becomes apparent when we con- sider that in the Monadologia geomet y was accepted as an ultimately trustworthy description of space. Now Kant must have realized that geometry in its practical application has to do with the world of sensory experience. But if sensory experience is very likely to be misleading, then geometry - whose certainty was unquestioned - could not derive its validity from such experience. But if sensory For this dispute cf. Klaus Reich, Introduction to Kant, De mundi etc., Hamburg 1958, pp. VII ff. 167 experience is very likely to be misleading, then geometry - whose certainty was unquestioned 4 could not derive its validity from such experience. On the other hand. geometry could also not be validated through a metaphysics whose principles run counter to the doctrines of geometry. In the Monadologia, metaphysics and geometry were considered. as it were. as two independent and equally certain branches of speculation whose reconciliation is attempted. But as Kant's attention was drawn to the importance of sensory experience. the problem of the application of geometry to sensory experience and its validation -- not as a piece of speculation but as an applied science -- becomes of pivotal importance. That geometry could in fact be applied to empirical objects was, of course, commonplace; but if geometry applied universally and unrestrictedly to experienced objects, and if these objects were thought to be continuous, then they could not have simple extended parts, at least not as experienced objects. But bodies as such did have Simple parts. as had supposedly been shown in the monadolggia physica. In summary, the difficulties that Kant realized after his encounter with Hume stemmed largely from the fact that sensory experience. relegated to insignificance in the early writings. rose in status. and that geometry was recognized 168 not to apply to things as metaphysics showed them to be, but to the world of sensory experience. We may say that it is to Hume's credit that Kant recognized. and attempted to resolve, the unfinished business of the monadologia physica. This task was undertaken in the inaugural dissertation of 1770, De mundi sensibilis acque intelligibilis forma et principiis.176 Thus the Dissertation. as later the Trans— cendental Esthetics. was meant to .esolve two problems at the same time. namely the divergence between the metaphysical and empirical accounts of matter. and the validation of geo- metry. Moreoever, the suggestions made to this end are very similar to those put forth in the Transcendental Esthetics. In both accounts it is clearly stated that a distinction must be made between things as they appear and things as they really arel77 and. in addition, the Dissertation endea- vors for the first time to explain why things appear as they do. As far as the perception of objects in space is concerned, it is asserted that: The concept of space is a pure intuition... It is not put together from sensations, but is the fundamental form of all outer sensation. This 176Akademieausgabe. Vol. II, pp. 385-419. See also note above. Ibid., p. 392. Handyside. o . cit.. p. 44. 169 pure intuition can be readily observed in the axioms of geometry. and in every mental construce tion of postulates or of problems.178 and Space is not something objective and real, neither substance, nor accident. nor relation, but subjective and ideal; and, as it were. a schema, issuing by a constant law from the nature of the mind, for the co-ordinating of all outer sensa whatsoever.179 This theory does not only offer a ground for the validation of geometry, but it also explains why geometry ' is applicable to the world of experience: Thus, as regards all properties of space which are demonstrated from a hypothesis not invented, but intuitively given as being a subjective condi— tion of all phenomena, nature is meticulously conformed to the rules of geometry, and only in accordance with them can nature be revealed to the senses. Here as later, Kant explicitly rejects the notion that geometry is derived from experience, and thus places himself in direct opposition to Hume. He points out: Unless the concept of space had been given originally through the nature of the mind, the use of geometry in natural philosophy would be very unsafe; for it would be poSsible to doubt whether the notion of space obtained from experience will 179 Ibid., p. 403. Handyside op. cit.. p. 61. 190 Ibid»; p. 404,-Handyside, o . cit., p. 63.. 170 sufficiently harmonize with nature, the determina- tions from which it has been abstracted being per- chance denied.181 In fact, the theory which would derive geometry from experience is the only rival account of the validation of geometry discussed in the Dissertation. It would indeed explain why geometry applies to experience: because it is abstracted from it. But it lacks the desired universality and certainty which geometry de facto possesses, since any generalization derived from experience has only a more or less high level of confirmation, and can be invalidated “if the determinations from which it has been abstracted...(are) per— chance denied." The theory of geometry so far expounded is well known, being identical in substance with that put forth in the Transcendental Esthetics. It differs widely from the con- siderations offered in the monadologia. It must be noted that in this new account sensuous knowledge is no longer regarded as necessarily confused. It is wrong to regard the sensitive as that which is more confusedly known, and the intellectual as that of which our knowledge is distinct...for 1811bid., p. 404f., Handyside, 09. cit.. p. 63. Cf. David Hume, A Treatise of Human Nature. ed. Selby — Bigge, Oxford 1955, p. 71. 171 that matter, the sensitive may be very distinct, and the intellectual extremely confused. This is shown, on the one hand by geometry, the pro- ,totype of all sensitive knowledge, and on the other hand by metaphygécs, the instrument of all things intellectual. In the monadologia.the admission of the distinctness of sensitive knowledge would have caused considerable diffi- culties. While the monadologia assumes that differences exist between the appearance and the real character of things, the difference was put to the confusion of sensory experience. Now, the difference is still recognized. but it is said to be due to the fact that all sensitive knowledge is subject to certain clearly recognizable forms. However, if objects appear different from what they really are. how can the recognition of their phenomenal character be called "know- ledge"? Since things are different from their appearance, does not the old charge that sensitive knowledge is confused still hold? Would one not have to admit that beliefs formed about phenomena are deceiving, since the things in themselves do not agree with these beliefs? Kant answers this objection in an exemplary fashion by observing that to take judgments about what is known by sense, the truth of the judgment consists in the agreement of its predicate with the given subject. But the 182 .. Ibid., p. 394f.. Handyside op. cit.. p. 47f. 172 concept of the subject, so far as it is a phenomen- on, can be given only by its relation to the sensi- tive faculty of knowledge; and it is by the same faculty that sensitively observable predicates are also given. Hence it is clear that the representa- tions of subject and predicate arise according to common laws, and so allow a perfectly true knowledge. Thus the senses are capable of delivering perfectly precise knowledge about phenomena. The passage does not need any further explanation but its decidedly modern flavor deserves to be noted. However, now the difficulties come to a head. If sensitive knowledge can be precise, and intellectual know- ledge can also be precise, then the accounts of the composi- tion of matter derived from both these sources must either be in agreement, or. if they are not, an explanation must be forthcoming why they differ. Unfortunately, the accounts are not in agreement. Matter as perceived must obey the laws of geometry, which asserts continuity of its bodies, and to be continuous, according to Kant, is to have no ulti— . . 184 mate parts, although the continuous 18 a compound. On the other hand, matter when considered as a compound and apart from the conditions of its sensory perception 183Ibid., p. 397, Handyside op. cit., p. 51. 184Ibid., p. 399, Handvside op. cit., p. 54. 183 173 must contain simple parts: “...the intellect proves that given a complex of substances, there are given also elements of composition, i.e. simples."185 It must be noted that in these two conflicting accounts we have a statement of the second antimony. In order to see how a resolution of this antinomy is attempted in the Disser— tation, we must turn to the opening passages of that work. Kant here makes a distinction between the operative and the conceptual formation of the concept of a whole. Since he does not distinguish between classes and wholes, he claims that the composition in the latter case is achieved through the class concept, but in the case of the operative formation (synthesis) of the concept of a whole, the process depends on the conditions of time. since it requires the successive addition of part to part. Thus, to venture an example, the conceptual formation of a certain whole (class) e.g the class of brown horses and blown cows, is achieved through the class concept, i.e. "pro- duct of the class of brown things with the sum of the class of horses and the class of cows." The operative formation of the concept of that whole proceeds by "taking account" in 185 Ibid., p. 415. Handyside. op. cit., p. 79. 174 one form or another. of each member of that class, where the whole finally emerges as "the class of all those things of which I have here taken account (whnzh I have added together)". For our purposes more impOrtant than the case of compo- sition is the similar situation that obtains with respect to decomposition. Here again Kant contrasts a conceptual decomposition with an operative decomposition. Given a complex of substances, we easily reach the idea of simples by completely removing the intellectual notion of composition; for it is simples that remain when all conjunction is abolished. But according to the laws of intuitive knowledge, the case is different; composition is not removed completely save by a regress from the given whole to all possible parts whatsoever, in other words, by an analysis which again rests on conditions of time.186 Such a decomposition can be carried out fully only if the process can be terminated within a finite time. But the continuum is of such a character that its decomposition cannot thus be brought to an end. But since in the continuous quantum the regress from the whole to its possible parts... finds no end...the analysis...will be impossible of completion. The whole cannot. in conformity with the laws of intuition, be apprehended by an exhaustive division of parts. 186Ibid., p_ 387, HandYSide, on. cit.. p. 36. 187 ' Ibid., p. 388. Handyside, o . cit.. p. 36. 175 In order to understand the force of this argument, it must be recalled that both space and time are given as pure intuitions and that, moreover, they are the forms under which phenomena appear. This means that the conceptual decomposi- tion of space or time, and of objects given in space and time cannot be achieved; or, to put it otherwise, it is not permissible to argue that an object given in intuition, i.e. under the form of space. consists of simple parts, if it is complex. This argument holds only for complexes given, not th;ough intuition, but through the intellect. Thus, as far as objects in space are concerned, one cannot "reason out" what their ultimate parts are, nor that they have ultimate parts at all. and the reason for this is that the primary properties of space and time are, as it were. non-discursive. Kantpoints out: “All primary properties of these concepts (i.e. space and time) are beyond the juiisdiction of reason, and so cannot in any way be intellectually explained." Hence, if a division of space, or of an object in space is to be undertaken, or if it is to be made out of what space or objects in space are composed, one must avail oneself of that method which is appropriate to objects given in 1881bid., p. 405, Handyside, o . cit., p. 64. 176 intuition. i.e. operative decomposition. Thus, according to Kant. operative decomposition is the only way in which any— thing can be made out about the parts of a continuum. But such a decomposition can never come to an end in such a case. and this is precisely what characterizes continua. The reason why this decomposition cannot come to an end lies in the following: Every division of a body or spatial region :reguires a finite time. Hence, if the dividing game has been f, and depends for its existence on, Simples. On the other Tiand, not all complexes are complexes of substances, and hence 1 94Critique of Pure Reason, A 525, B 554. 184 the conclusion that all complexes consist of simples is fallacious The latter holds in particular for continua. Here then lies Kant's solution to the problem of the continuum: As in Leibniz, an intelligible world of noumena is distinguished from a phenomenal world. Continua occur only in the latter, but since they have their origin in intuition, not much can be made out about them discursively. But intuition, being subject to the limitations of time is also incapable of breaking down a continuum to its ultimate parts, so that it becomes meaningless to speak of the ultimate parts of the continuum. Noumena, or things in themselves cannot be said to be continuous. Of them it can therefore confidently be asserted that, if they are composite, they have Simple parts. A word of caution is here in place. When it is ‘asserted that a series of divisions of a given continuum can, in principle, be infinitely extended, i.e. that the operation of division cannot have a final member, then this is not to mean that there is an infinity of parts already given in that continuum. Any intuition is always given as a whole, in one act of intuition. In the successive steps of its operative decomposition more and more of its parts are realized. But Since a given continuum is nothing but an 185 intuition, and nothing but ong_intuition, we cannot say that these parts were already there before the operative decompo- sition began. Thus it can be said that a continuum can be divided ad infinitum, but not that it "has" infinitely many parts.195 This point is made so often, from the Dissertation to . O . . . the MetaphySische Anfangsgruhde, and Kant is so inSistent upon it that it is quite obvious that he attached a good deal of importance to it. And justifiably so, for he regarded the assumption of an actual infinite in a finite object as incon- . .0 Sistent. In the Anfangsggunde he flatly asserts that "there is no real infinite number (of parts) in the object (which ‘ would be an explicit contradiction)."196 In the Critique 0‘ Pure Reason he tries to give a ground for this assertion by saying: In the case of an organic body conceived as organized in infinitum the whole is represented as already divided into parts, and as yielding to us, prior to all regress, a determinate and yet infinite number of parts. This, however, is self- contradictory. This infinite involution (Entwicklung) is regarded as an infinite (that is never to be completed) series, and yet at the same time as completed in a complex (Zusammennehmung). 195 Cf. Critique of Pure Reason, A 513f, B 541f; and A 524E, B 552f. 196 Akademieausgabe, Vol. IV, p. 507. 197Critique of Pure Reason, A 527, B 555. 186 That this argument is fallacious can easily be shown. In order to avoid problems that arise from higher orders of infinity let us consider the set of rational numbers larger than or equal to l and smaller than or equal to 2. This set has 1 and 2 as its smallest and largest member respectively, and it contains infinitely many members. A one to one correspondence between it and the set of positive integers can be demonstrated. But to argue that there cannot be infinitely many rational numbers between 1 and 2 because the set of integers has no last member is clearly a non sequitur. But this is what Kant's alleged proof amounts to. One could perhaps surmise that Kant's denial of the simultaneous infinite was brought about through Leibniz' contention that there is no infinite number, which we have discussed above. In that case we would find in Kant again some ihfluence of Galileo's paradox. This surmise receives some lilelyhood from the fact that Leibniz frequently asserts that an infinite number of parts in an object is impossible, while only occasionally stating his reasons for this assertion. Be this as it may, Kant's denial of the }- actual, simultaneous infinite can be said to have had pro- found influence upon the structure of his system, whatever his reasons for this denial might have been. 187 The theory so far discussed is that represented int the Dissertation. In my exposition I have made use of material from the Critique of Pure Reason only for elucidatory purposes, and I feel justified in having done so since I cannot perceive any fundamental difference between the theories of the Dissertation on one hand, and the Transcendental Esthetics and the discussion of the first two antinomies on the other. The first Critique goes beyond the dissertation in that it gives a clearer statement of the antinomies to be resolved, but the resolution, at least of the first two antinomies, is undertaken entirely within the framework already provided by the Dissertation. iat is left for us to do, then, is to consider the Second Antinomy, and to see how, precisely, its resolution is attempted. The Second Antinomy is stated thusly: Thesis: Every composite substance in the world is made up of simple parts, and nothing any- where exists save the simple or what is composed of the simple. Antithesis: No composite thing in the world is made up of simple parts, and there nowhere exists in the world anYthing simple.198 By the term 'world' is here meant 'the sum Of all 199 appearancesg. which, according to Kant, makes the_thesis 19RCritique of Pure Reason, A 434, B 462. 199CE. Critique of Pure Reason, A 419, B 447. 188 false. The thesis would hold only of things in themselves, but these do not belong to the world defined as the sum of appearances. On the other hand, the antithesis is intended to come out true, with the understanding that 'world'. again, means 'the world of appearances.‘ Thus the conflict is removed Since the thesis is true only for things in themselves, the antithesis only for appearances. y. A difficulty arises from the fact that Kant seems to claim, on at least one occasion, that both thesis and anti- thesis are false. He points out that "the suit in which reason is implicated...has been dismissed as resting, on 200 both Sides, on false presuppositions." Now we have seen that the thesis is clearly meant to be false, owing to the restriction of 'world' to appearances. The antithesis, however, is meant to be true, if the term 'world' is used in the same restricted sense; it amounts to the claim that among appearances simples can nowhere be found. I believe that what Kant assails as resting on false presuppositions is not the position stated in the antithesis, \ nor, for that matter, that stated in the thesis, but doctrines 200Critique of Pure Reason, A 530, B 558. 189 that would arise, if by 'world' were meant, not 'the sum of all appearances, but 'the sum of all there is'. In this case, the thesis would be false because it is not considered to hold of appearances, and the antithesis would be false, since it supposedly does not hold of things in themselves. Thus, a conflict arises only if the claims, either for thesis or antithesis, are overextended, as would be the case if the teim 'world' were meant to refer to all there is. We have seen above what Kant's reasons were for accept- ing the doctrine of the thesis for things in themselves, and that of the antithesis for appearances, but a short summary is here in place. In the early Kant the problem of the composition of matter was construed as a problem about the intelligible world. Kant assumed then that any piece of matter, considered in itself, is made up of a finite number of ultimate parts, while the space in which such matter is located is infinitely divisible. Since appearances do not agree with the meta— physical description of matter, it must be assumed that sensory experience is confused. This doctrine was put in jeopardy by the realization that geometry applies unre- strictedly to objects as they appear, and since geometry demanded the infinite divisibility of its lines and bodies, 190 the same would have to hold of any and all objects in space. The unrestricted application of geometry to spatial objects was considered justified through the assumption that space is the form of all outer experien e, and that the axioms of geometry are an accurate description of the pure intui- tion of space. As long as the doctrine of infinite divisi- bility applied only to purely geometrical entities it was perhaps not as pressing to the metaphysician as now, when this same doctrine was to hold of any objects in space. The solution was made more difficult through the assumption that it is contradictory to assume an infinity of parts in a finite object. The conflict was finally resolved through the introduction of the notion of operative decomposition: bodies in appearance are originally always given as gngJ and they have only as many actual parts as are in fact realized through successive steps of operative decomposition. That there is no lest utep in this decomposition is guaranteed by a so-called rule of reason. Thus bodies are said to ~ A be divisible ed Sgginigufl without therefore having an infinity of actual_parts. fi;s whole scheme required that bodies are not something in themselves, because only if they are not things in themselves can it be assumed, so Kant thought, that the parts do not precede the actual division. If they 191 were things in themselves an infinite division in the object would have to be assumed, which was held contradictory. Kant's theory was not only meant to resolve the problems of the continuum as far as the constitution of (continuous) bodies is concerned, but it was intended also to settle the issue for continua as they occur in pure geometry. For these the same considerations would hold, since they, too, are objects that occur in intuition. albeit in pure intuition. Thus we can see how the doctrine of the Transcendental Esthetics is a proposal which, in Kant's opinion, would satisfactorily resolve the problems of the composition of the continuum. CHAPTER V BERNARD BOLZANO In the preceding chapters I have attempted to show that some well-known philosophical systems of the Seventeenth and Eighteenth century were constructed in such a way that in them certain problems connected with the continuum and with infinite sets did not arise. In all those systems such problems were of central importance, as I hope to have shown, but they were by no means the only problems to be discussed: .m» they were always transacted in a larger context. We saw that they arose in connection with the problem of the con- stitution of matter, of space or of time, and that their solution was attempted through metaphysical or epistemological considerations. In Bolzano this is, for the first time, no longer the case. Bolzano addresses himself explicitly and directly to the problem of infinite sets in general, and of continuous sets in particular. Even through a casual perusal of Bolzano's work one becomes impressed with the forthrightness and com- parative precision with which he states his problems and attacks them. It seems that this very fact earned him the contempt of many of his contemporaries. I believe that this ‘\ 193 is largely due to the influence of Kant's philosophy. Bolzano actually addresses himself to several of the problems with which Kant was originally concerned, and for which Kant supplied his own particular solutions. But it was Kant's solutions, rather than his problems, that directed the philosophical enquiries of his recognized successors. A passage from a review 0: Bolzano's Wissenschaftslehre bears testimony to this: The standpoint of the author is throughout the old one, which is called strictly objective, also dogmatic, in contradistinction to the con- temporary one which is based on the psychological self-consciousness of the thinking mind. In the face of much derogatory twaddle, Bolzano continued to deliver his philosophy from the outmoded objec- tive standpoint, and one of the fruits of his labor is his epochmaking, though by no means definitive Paradoxes of the 202 Infinite. 201?. Menelaos (probabl; a .om de plum), Review of Bolzano's Wissenschaftslehre, Zeitschrift r3: Philosophie und Katholische Theologie, Heft 25. Quoted from Dr. Bolzano und seine Gegner, Sulzbach (Seidel) 1839, pp. 157E. 202 Bernard Bolzano, Paradoxien des Unendlichen, (ed. Fritz Prihonsky), Hamburg (Felix Meiner) 1955, lst. ed. Leipzig 1851. Translated as Paradoxes of the Infinite (translated and ed. by Donald A. Steele, S.J.L London (Routledge and Kegan Paul) 1950. This work was published posthumously (Bolzano died in 1848), and there is a likely- hood that Prihonsky did some editing which, at least on 194 This work is known chiefly for the fact that in it Bolzano states again several examples of the Paradox of Galileo, and generally embraces the position that all infinite sets have subsets to which they stand in biunivocal correspondence. Bolzano thought that he had, for the first time, discovered this property: We now pass on to consider a very remarkable peculiarity which can occur in the relation between two sets when both are infinite. Properly speaking it always occurs, but to the disadvantage of our insight into many a truth of metaphysics as well as physics and mathematics, it has hitherto been overlooked. Even now, when I come to state it, it will sound so paradoxical that we shall do well to spend some time over its investigation. I assert the following: When two sets are both infinite, then they can stand in such a relation to one another that: one occasion, led to a palpable falsification. Bolzano him- self had prepared for publication a manuscript on the theory of functions which was published in 1930 (Functionenlehre, Prague 1930), in which he gives an explicit example of a continuous, non-differentiable function, while the paradoxes declare (Footnote § 37) that all continuous functions are differentiable, except for isolated points. The discrepancy was first discovered by Jasek. Cf. Introduction to Paradoxes of the Infinite, p. 54). It was generally held at the time that all continuous functions are differentiable, so that it can be unde stood how Prihonsky, a man of limited mathe- matical background could have added an "explanatory" footnote to that effect. On the other hand, in the present paper we are concerned with doctrines, the ingenuity and novelty of which point clearly to Bolzano as their author. Moreover, there are a large number of points of agreement between the Paradoxien and the Wissenschaftslehre (Bernard Bolzano, Wissenschaftslehre, 4 vols., Sulzbach (Seidel) 1837). In particular, the definition of "continuum" is identical in both accounts. 195 (i) it is possible to couple each member of the first set with some member of the second in such a way that, on the one hand, no member of either set fails to occur in one of the couples; and on the other hand, not one of them occurs in two or more of the couples; while at the same time (ii) one of the two sets can comprise the other as a mere part of itself.203 Now we have already seen that Bolzano was mistaken in assuming that he was the first to notice this relation, since both Leibniz and Berkeley were aware of it in its generality, while Galileo knew at least an example.204/ What is new is that Bolzano did not think that this property makes the existence of infinite sets impossible; in other words, he no longer regards the sweeping acceptance of Euclid's part-whole axiom as justified. This attitude of Bolzano's, of course, rests on his recognition that the assertion of the biunivocal corres- pondence of an infinite set with one of its proper subsets does not introduce any obvious contradiction into mathematics, provided that Euclid's axiom is properly understood. Bolzano's \ merit lies, then, not in his having discovered this feature 203Bolzano, Paradoxien, § 20, p. 27 f. 204Jourdain is consequently mistaken when he writes that "this curious property of infinite aggregates was first noted by Bernard Bolzano" (Philip E. B. Jourdain (ed.) 9927 tributions_tp.the,Eounding of the Thegry of Transfinite Numbers, by Georg Cantor, New York (Dover) 1915, editor's introduction, p. 41). 196: tn 0 infinite sets, but in that he, for the first time, placed enough trust in the procedures of mathematical enquiry simply to accept it as a fact, rather than to con- front it with bewilderment as his philosophical precursors ,- had done. Thus we must criticize Fraenkcl ior assuming that Bolzano's Paradoxien were to be "a catalogue of, as it were lamentable, paradoxes which condemmsitself to fruit- 1essness."205 Actually, the Paradoxiea are a discussion of alleged paradoxes, of which the Paradox of Galileo is one. But their whole point is that here are only seeming paradoxes rt which a precise account of infinite se s will dispel. Lamentable is at most the fact that other philosophers found paradoxes were there are none. Bolzano makes it quite clear where the oddity of the Paradox of Galileo stems from: As I am far from denying, an air of paradox clings to these assertions; but its sole origin is to be sought in the circumstance that the mutual relation which we find between two sets when we can pair off their parts (members) with the previously mentioned result suff ces in every case where these sets are finite to “tablish their perfect equinumerosity of members. F1. 0 O" (D 2 05Abraham A. Fraenkel, Meugenlehre und Logik, Erfahrung und Denken, Vol. II, Berlin (Dunker und Humbiot), 1959, p. 10. 206Bolzano, Paradoxien, § 22, p. 31. 197 Let us consider, for the moment, only part of the import of this statement. What is asserted is that it sounds paradoxical to claim that infinite sets are in biunivocal correspondence to proper substes of themselves, but only because such a relation cannot obtain with finite sets. The latter fact is seen as an obstacle to the acceptance of the former, probably because we do not have any direct acquaintance of an intuitive or sensory sort with infinite sets. A more important feature of the above passage is that it adds to the assertion that all infinite sets stand in this relation to some of their proper subsets the converse of this assertion, namely that only infinite sets have this ‘property. However, this characteristic of infinite sets, namely that all and_only infinite sets can be brought in a one-to-one correspondence with proper subsets of them- selves, is not taken to be the definitive characteristic of infinite sets: Bolzano chose a different definition: "I shall call an infinite multitude one that is larger than any finite magnitude, i.e. one of which any finite set represents only a part."207 L fifi 207Bolzano, Paradoxien, § 9, p. 6. 198 I can see no objection against this procedure, which first defines 'finite', and then employs the term 'finite' in (A. ”he definition of 'infinite', provided that a satisfactory definition of 'finite' is given. Balzano gives this defini— tion in the following passage: Let us consider a series whzse first term is an individual of the species A, and whose every subsequent term is derived from its predecessor by joining a fresh individual with the equal of that predecessor so as to form a sum. Then clearly all terms which occur in this sequence, with excep- tion of the first, which is a mere individual of the species A, will be multitudes of the species A. Such multitudes I call finite.208 w. This definition poses more problems than it solves. Setting aside minor inadequacies of expression, what is intended is obviously the following: Consider a set A of objects. Choose any member of A, for example k, and form the unit set {kt of k. Then either take k, and form a set consisting of k and some other element of A, say l. 0: else pick a set of members of A which has as many elements asl kl , i for example lm‘ , and form a set out of its members together with precisely one other member of A. In general, if N is a given set in the series, the next set is fcrmed either by taking the elements of N together with precisely one other element of A, or else by taking a set N' which is "equal" ' \ 2081bid.. § 8, pp. 5 ff. 199 to N and which is also a subset of A, and adding to the elements of N' another element of A. Clearly, the pro— cedure depends upon a definition of 'equal'. which is nowiere given, a fact that leads to other serious shortcomings, as we shall presently see. All sets in the series so generated are finite in the general, preanalytic acceptation of that term, but we do not therefore get a precise definition of 'finite', since obviously there are sets which neither occur in the sequence, nor fulfill the criteria for infinite sets. To remedy this situation, we would have to consider not just one set (species) A, but all setsthere are. and for each of these, except for the unit sets, we would have to form more than one series, since under the above described procedure for example.{l; , which is ordinarily considered a finite set, would nowhere occur in the series we were describing. ‘but even if all these amendations were made. we would still require a definition of equality, a proof that the choices here described can always be made and assurances that the consideration of all sets does not, in this case, lead to inconsistencies. I cannot here undertake a detailed discussiOn of these matters, but the above considerations show that Bolzanofs definition of 'finite set' is not tenable in the form in which it is given. To return to the di3cussion of infinite sets: We saw that Bolzano had recognized that all and only infinite sets stand in biunivocal correspondence to some of their proper subsets. It will be recalled that Cantor ascribed equal "power" (Machtigkeit) to sets that stand in such a relation to one another. Nowadays we generally call such sets equi— valent, Presumably, Cantor chose the word 'pcwer' in order to avoid such expressions as 'equal', or 'as large as', or ‘having as many members as', which might merely have involved him in fruitless quibbles. Cantor, however. nowhere asserts that of two sets which have equal power, one can be larger than the other, no matter how "obvious" this might seem. Bolzano had not reached this stage. He points out that if we pair off the members of two finite sets, and none remains in either set, then none of the two sets is larger than the other. Not so with infinite sets. Here, he claims, two sets can be in one-to-one correspondence, even though one is larger than the other.209 The mere fact...that two sets A and B are so related that every member a of A corresponds by some rule to some member b of'B in such wise that 209Ibid., 5 22, p. 31. 201 the set of couples.(a~b) contains every member r*f A or B once and only once, never justifies us... to infer the equality of the two sets with respect to the multiplicity of their members if these sets are infinite. The "obvious“ examples are the rational numbers between 0 and 5 and O and 12 respectively, and the points on a bounded line and on a proper part of that line. Although in both cases biunivocal correspondences can be established, Bolzano holds that there are "more" rational numbers between 0 and 12 than there are between 0 and 5. and a similar case is made for the two lines. One might think that Bolzano perhaps differed only in terminolognyrom the now generally accepted position. But in order to establish this conclusively, one would have to find out what, precisely, Bolzano meant by ‘equal in number', 'larger' etc. To judge from his examples, what he had in mind is the following: If A is a subset of B, then A is smaller (has fewer members) than B. If A and B have identical members. then they are equal. If this is all that can be supplied in definition of 'equal' and 'smaller', then we are forced to the assumption that certain sets cannot be compared with respect to the number of their Inembers: and Bolzano in fact asserts "whether there are 210 Ibid. 8 21, p. 30. / 202 more triangles or more syllogisms is indeed a question to which no answer can be given other than that one does not know how to compare these two infinite sets."211 The undesirability of Bolzano's approach becomes clear when we ask whether there are "more" (in Bolzano's sense) negative integers smaller than 0 than there are positive integers larger than 1. While he would assert that there are "more“ positive integers larger than 0 than there are larger than 1. he cannot meaningfully answer the first question at all. for if he were to pair off all negative integers smaller than -l with their positive counter- parts. in order to have -l left over. he would have estab- lished equinumerosity through-one-to-one correspondence. a procedure that he denies himself explicitely.212 Bolzano himself did not always heed his own injunction against assuming equinumerosity for biunivocally correspond- ing infinite sets. On one occasion he flatly asserts that there are as many square of integers as there are integers,213 211Bernard Bolzano,'fiissenschaftslehre. Vol. 1, p. 4385. 212Cf. Bolzano, Paradoxien, § 22, p. Bl. 213 Ibid.. § 33. p. 54. 203 and on another he claims that there are as many circular surfaces as there are circumferences.214 Let me now proceed to a discussion of Bolzano's views on continuity. He gives the same definition of 'continuous' ‘in both the Wissenschaftslehre and the Paradoxien. He states that a continuum is present when, and only when, there is "a set (Inbegriff) of simple objects (of points in time or space, or even of substances) which are so situated that every single one of them has at least one neighbor for every 215 distance, however small." P In spite of its shortcomings, this definition enabled Bolzano to recognize certain important properties