Modality, ontology, and phenomenology : Leibniz’s multiple views on existence : a historical and analytic reconstruction

(1)

Scuola Normale Superiore di Pisa

OSVALDO OTTAVIANI CLASSE DI LETTERE E FILOSOFIA

A.A.2017-18

Modality, Ontology, and Phenomenology.

Leibniz’s Multiple Views on Existence

A Historical and Analytic Reconstruction

(2)

I

III and Existences in the Confessio Philosophi……….250 5.3 The Emergence of Alternative Possible Series. Leibniz’s Discussion with Steno (1677)……….…258 5.4 The Derivation of All Things from God. Logical or Causal Dependence? A Puzzle Concerning Leibniz’s Reading(s) of Spinoza………...268 5.5 The Aftermath. Leibniz on the Distinction between Essential and

Existential Requisites………...…………277 6. THE ORDER OF THE SERIES.LEIBNIZ’S DOCTRINE OF UNIVERSAL

CONNECTION……….…………. 286

6.1 Singularium essentialis ordinatio. A Framework for Existence………287 6.2 The Genesis of The Notion of Universal Connection: Leibniz and the

Paradox of the ‘Full Cause’……….…………...302 7. LEIBNIZ ON THE PLURALITY OF WORLDS………324

7.1 Non nisi unum est genus mundi. Leibniz’s Tantalizing Argument :

An Overview………..324 7.2 From the ‘Dream Argument’ to the Plurality of Worlds.

Leibniz’s Reflection of April 1676………...…………340 7.3 Indexicality and Actuality. Leibniz’s Egalitarian Temptation……….……….352 7.4 Divine Wisdom and Cosmological Order. A Theological Argument against the Plurality of Worlds………..…………366 7.5 Mira ratiocinatio. Leibniz’s Philosophical Argument against the Plurality of Worlds………..………….375 7.6 Leibnizian Actualism……… 395 7.7. Addendum: Space, Time, and the Original Limitation of Creatures………….399

3 Section III: Between Ontology and Modality. Leibniz’s

Account of Existence and Existential Propositions………...…….404

8.REALITY,IDEALITY, AND ACTUALITY.AMAP OF LEIBNIZ’S

DISCUSSION ABOUT EXISTENCE………..………..409

8.1 The ‘Existence’ of Essences in Leibniz’s Letter to

Foucher. Between Plato and Malebranche……….……….409 8.2.Real Essences and Ideal Entities. The Case of Mathematical Objects….….415 8.3. Ideal Entities. From Mathematical Objects to General Essences …….…….422 8.4. Divine Ideas/1: Leibniz’s Discussion with Wagner………...…428 8.5. Divine Ideas/2: Exemplars or Representations?...436 8.6. The Puzzle of Existence Revisited……….448 8.7. Existentia possibilis. The Clash between Modality and Ontology…….…...466 8.8. A Twofold Account of Possibility: Pre-and Post-Existential One……..…..478 8.9. Possibilities and Possible Individuals………..…..489

(5)

IV Appendix: Suárez on Divine Ideas, Exemplars, and Possibila……….500

9. POSSIBILIA,ESSENCES,AND PROPOSITIONS. LEIBNIZ AND THE

PROBLEM OF NECESSARY BEING(S)……….505 9.1 Platonism about Essences in the Correspondence

with Eckhard (1677)………..505 9.2. A parte rei/1. The Necessary Existence of Propositions in 1677……….511 9.3. A parte rei/2. Platonism, Existence, and Eternal Truths in the

Probatio (1678)……….526 9.4. Perelegans sophisma. Leibniz against the Proliferation of

Necessary Beings………...530 9.5. De propositionibus existentialibus/1. A New Account of

Existential Propositions?...535 9.6. De propositionibus existentialibus/2. The Sophism at Work………544 9.7. Inesse, Conceptual Containment, and The Equivalence between Terms

and Propositions ... ...554 9.8. Is Existence a Reducible Notion? ... ...563

Appendix A: On Leibniz’s Formal Proof of the Equivalence between

Categorical and Hypothetical Propositions……….…….582 Appendix B: Essential and Existential Propositions in the

(6)

V

Abbreviations

A = Gottrfried Wilhelm Leibniz: Sämtliche Schriften und Briefe, Darmstadt, Leipzig and Berlin: 1923 (ongoing). Quoted by series, volume and page number (e.g. A VI 4, 543);

AG = G. W. Leibniz, Philosophical Essays, transl. and ed. by R. Ariew and D. Garber, Indianapolis, 1989;

Ak = Kants Gesammelte Schriften, Deutsche Akademie der Wissenschaften, 29 vols., 1900-. Quoted by volume and page number (e.g. Ak II, 236);

AT = Oeuvres de Descartes, ed. C. Adam and P. Tannery, Paris, 1897-1913. Quoted by volume and page numbers;

Anti-White = T. Hobbes, Critique du De mundo de Thomas White, introd. and critical text by J. Jacquot and H. Whitmore Jones, Paris 1973;

Beeley = G. W. Leibniz, J. G. Wachteri de recondita Hebraeorum philosophia (1706), edited by P. Beeley, The Leibniz Review, vol. 12, 2002, pp. 1-14;

Cout. = Opuscules et fragments inédits de Leibniz, ed. Louis Couturat, Paris 1903 ; reprint, Hildesheim 1966 ;

CP = G. W. Leibniz, Confessio Philosophi : Papers Concerning the Problem of Evil, 1671-

1678, ed. and transl. by R. C. Sleight, New Haven 1992;

CW = Spinoza, Complete Works, transl. by S. Shirley, ed. with an introduction and notes by M. L. Morgan, Indianapolis 2002;

DAC = Dissertatio de arte combinatoria (1666), A VI 1, 163-230/GP IV, 15-26. Quoted according the number page of A and GP;

DPI = Disputatio metaphysica de principio individui (1663), A VI 1,10-19/GP IV, 15-26 Quoted according to A and GP;

(7)

VI Cottingham, R. Stoothoff, and D. Murdoch, Cambridge 1985. Quoted by volume and page number;

Discourse = G. W. Leibniz, Discourse de métaphysique, A VI 4, 1529-88, quoted

according to A ;

DM = F. Suárez, Disputationes metaphysicae, 2 vols., Hildesheim 1966 (reprint of the corresponding vols. 25 and 26 of the Vivès edition of the Opera omnia, Paris 1866). An amended version of the text of Suárez’s 54 disputations is now available on line: http://homepage.ruhr-uni-bocum.de/Michael.Renemann/suarex/index.htm]. Quoted by number of disputation, section, and paragraph (e.g. DM V, ii, 3);

DPG = G. W. Leibniz. Dissertation on Predestination and Grace, transl. and ed. by M. J. Murray, New Haven and London 2011. Quoted according to the number of the paragraph and the letter of the sub-sections of each paragraph, e.g. ‘# 25 (b)’ refers to Leibniz’s remarks on sub-section b of paragraph 25 of Burnet’s text;

DSR = G. W. Leibniz, De Summa Rerum: Metaphysical Writings, 1675-1676, trans. And ed. by G. H. R. Parkinson, New Haven and London 1992;

EW = The English Works of Thomas Hobbes of Malmesbury, edited by W. Molesworth, 11 vols., different editors 1839-45; reprint Aalen Ger. 1962. Quoted by volume and page;

Fichant = G. W. Leibniz, De l’horizon de la doctrine humane-La Restitution Universelle, unpublished texts ed. and transl. by M. Fichant, Paris 1991 ;

G = Spinoza Opera, ed. C. Gebhardt, 5 vols., Heidelberg 1925. Quoted by volume and page;

GI = Generales Inquisitiones de Analysi Notionum et Veritatum (1686), A VI 4, 739-88 Quoted according to A, reference goes to the translation in LP ;

GM = Leibnizens mathematische Schriften, ed. by C. I. Gerhardt, 7 vols., Berlin 1849-63. Quoted by volume and page number;

GP = Die Philosophischen Schriften von G. W. Leibniz, 7 vols., ed. C. I. Gerhardt, Berlin 1875-90. Quoted by volume and page number;

Gracia = Suárez on Individuation. Metaphysical Disputation V : Individual Unity and its

Principle, transl. by J. E. Gracia, Milwaukee 1982;

Grua = G. W. Leibniz, Textes inédits d’après les manuscrits de la Bibliothèque provinciale

de Hanovre, 2 vols. (but with continuous pagination), ed. G. Grua, Paris 1948. Quoted

(8)

VII H = G. W. Leibniz, Theodicy, transl. by E. M. Huggard, New Haven 1952; reprint, La Salle 1985.

Jolley = G. W. Leibniz, Ad Christophori Stegmanni Metaphysicam Unitariorum, unpublished text, edited by. N. Jolley, “An Unpublished Leibniz Manuscript on Metaphysics”, Studia Leibnitiana, 7, 2, 1975, pp. 161-89. An English translation has been provided by N. Jolley in the appendix of his Leibniz and Locke. A Study of the

New Essays on Human Understanding, Oxford 1984, pp. 205-6. Quoted by page of the

Latin edition.

L = G. W. Leibniz, Philosophical Papers and Letters and Letters, transl. and ed. by L. Loemker, second edition, Dordrecht 1989.

Lalanne = Les Annotations de Leibniz à la Dissertation sur la Prédestination et la Grâce de

Gilbert Burnet, unpublished text, translation and transcription by A. Lalanne, in

www.philosophiedudroit.org. Same text printed in DPG, but Lalanne’s transcription is more accurate and presents also many relevant modifications and changes Leibniz made to the text.

LC = G. W. Leibniz, The Labyrinth of the Continuum: Writings on the Continuum

Problem, 1672-1686, ed. and transl. by R. W. Arthur, New Haven 2001.

LDB = The Leibniz-Des Bosses Correspondence, transl. and ed. by B. C. Look and D. Rutherford, New Haven 2007;

LH = E. Bodemann, Die Leibniz- Handschriften der Königlichen öffentlichen Bibliothek

zu Hannover, 1895; reprint: Hildesheim 1966. The first digit after ‘LH’ always

refers to the chapter divisions as set out in the ‘Inhalt’ of Bodemann’s catalogue. The other digits refer to successive divisions in Bodemann’s organization of the

manuscripts. The last digit always refers to a folio, followed by ‘r’ (recto) or ‘v’ (verso) when appropriate;

LP = Leibniz. Logical Papers, transl. and ed. by G. H. R. Parkinson, Oxford 1966;

LSS = Leibniz and the Two Sophies: The Philosophical Correspondence, edited and transl. by L. Strickland, Toronto 2011;

LST = The Shorter Leibniz Texts: A Collection of New Translations, transl. and ed. by L. Strickland, London 2006;

LW = Briefwechsel zwischen Leibniz und Christian Wolff, edited by C. J. Gerhardt, Halle 1860;

MLI = L. B. Mc Cullogh, Leibniz on Individuals and Individuation. The Persistence of

(9)

VIII translation of DPI);

Monadology = The Principles of Philosophy, or Monadology (1714), GP VI, 607-23.

NE = G. W. Leibniz, New Essays on the Human Understanding, transl. by J. Bennett and P. Remnant, Cambridge 1996. Quoted according to the page number in A VI 6 (included in the margin of this translation).

OL = Opera philosophica quae latine scripsit Thomae Hobbes malmesburiensis, ed. by W. Molesworth, London 1839-; reprint Aalen 1961. Quoted by volume and page number. PNG = Principles of Nature and Grace, Based on Reason (1714), GP VI, 598-606. PW = G. W. Leibniz. Political Writings, ed. and translated by P. Riley, second edition, Cambridge 1987.

Robinet = Malebranche et Leibniz: Relations personelles, ed. by A. Robinet, Paris 1955. Ross = F. Suárez, On Formal and Universal Unity, transl. by J. F. Ross, Milwaukee 1964. VE = Gottfried Wilhelm Leibniz. Vorausedition zur Reihe VI Philosophischen Schriften der

Ausgabe der Akademie der Wissenschaften Berlin, 10 fascicules with continuous

pagination. Quoted by page number.

Vivès = R. P. Francisci Suarez e societate Jesu Opera Omnia, 28 vols., edited by C. Berton, Paris 1866 (the whole Vivès edition is available on line:

http://cdigital.dgb.uanl.mx/la/1080042136_C/1080042136_C.html ). The text is printed on two columns, usually referred to as ‘a’ and ‘b’. Quoted by reference to volume, page and column number (e.g. Vivès, I, 210 a);

Vollert = F. Suárez, On Various Kinds of Distinctions, transl. by C. Vollert, Milwaukee 1947;

Wells = F. Suárez, On the Essence of Finite Being As Such, On the Existence of That

Essence and Their Distinction, transl. by N. J. Wells, Milwaukee 1983;

The titles of Leibniz’s works are given in the original language of the text cited. No distinction is made between Leibniz’s original titles and the editors’ title (even though, when relevant, this fact is mentioned in the text). Unless otherwise specified, translations are mine.

(10)

1

Introduction:

The Puzzle of Existence.

From Russell to Leibniz

“Non moltum interest quomodo Scientias partiaris, sunt enim corpus continuum quemadmodum Oceanus” (Introductio ad encyclopediam arcanam, A VI 4, 527) “Car il faut savoir que tout est lié dans chacun des Mondes possibles : l’Universe, quel qu’il puisse être, est tout d’une pièce, comme un Ocean […] “ (Essais de Théodicée, # 9, GP VI, 107)

1. Russell on Leibniz on Existence

“There is no more thorough-paced philosopher than Leibniz, and the relations of essence and existence are the very crux of his system; yet he tells almost nothing about Existence except that it is contingent and not a predicate, and he half retracts these. He never intimates, for example, how he can tell that he is a member of the existent world and not a mere possible monad on the shelf of essence”.1

This quotation, taken from a paper by D. C. Williams –devoted to a defence of the Humean claim that ‘existence makes no difference’, and, therefore, one could and should dispense with the notion of existence at all –deserves to be quoted just because is the best and most terse summary I know of the whole series of problems that shall be discussed in these preliminary remarks and, also, constitute the leading thread of my inquiry into the Leibnizian notion of existence throughout this work. Williams’ account, however, is not original, but, as he himself fairly acknowledges, is just a summary of the conclusions reached by B. Russell in his seminal book on the philosophy of Leibniz (published for the first time in 1900). This is not a coincidence, however, since, as I would like to point out here, the whole debate about Leibniz’s views about existence might be regarded as one concerning the acceptance or the rejection of Russell’s view.

As summarized in the passage above, Russell’s thesis is that, according to what he takes to be Leibniz’s considered view, existence is to be taken as (a) contingent and (b) not being a predicate (this is Russell’s original terminology; I will interpret it as the claim that existence is not a property of individuals, see below), or, alternatively, as a sort of anticipation of Kant’s view that existential propositions are synthetic rather than analytic ones. The peculiarity of Leibniz’s account, according to Russell, is the fact that existential propositions also represent

1_{D. C. Williams, “Dispensing with Existence”, The Journal of Philosophy, vol. 59, 23, 1962, 748-63, pp.} 751-52.

(11)

2 the whole of synthetic propositions (there are no synthetic propositions but existential ones). Russell, however, added that Leibniz’s views on both these two points were not always consistent, since there are texts in which he speaks in favour of existence as a predicate and, in some sense, as a necessary rather than contingent property.

In the first edition of his book, Russell’s diagnosis was that the internal consistency of Leibniz’s views was undermined by his (Leibniz’s) commitment to both the following opposite views: that the existence of finite things (i.e. individual substances) is contingent and is not a property analytically derivable from the notion of things themselves (i.e. from the complete individual notion of each individual substance); and that the existence of God, on the contrary, is necessary and derivable from his own essence, i.e. analytically contained in the concept of God, for Leibniz was a supporter of the ontological argument. From the point of view of the analysis of propositions, thus, whereas a proposition like ‘Peter exists’ has to be counted a synthetic and contingent, the proposition ‘God exists’ counts as analytic and necessary.2

This, in a nutshell, is Russell’s dilemma. One could object that it is not a genuine dilemma, however, for there is a third alternative left unexplored, i.e. that ‘existence’ is not an univocal notion, for we can legitimately say that ‘existent’ has not the same features in the case of divine existence as in the case of created things. Even though Leibniz is ready to accept a difference between necessary existence (in the case of God) and contingent one (in the case of created beings) –which is one of the main inconsistencies in Leibniz’s account according to Russell –, he clearly understands it as a distinction concerning the modal status of existence itself, not as a difference concerning the meaning of existence, for ‘existence’ is taken by Leibniz as an univocal rather than equivocal concept. On this point, therefore, Russell was right, for there are passages where Leibniz explicitly stresses the univocity of the fundamental metaphysical concepts, and, especially, of the concept of ‘being’.3

1.1 Russell on the Synthetic Nature of Existential Statements

A point that must be stressed about Russell’s analysis in 1900 is the Kantian perspective from which he moves. As Russell himself maintains, indeed, the distinction between necessary and contingent propositions is immediately understood in terms of the Kantian distinction

2_{Cf. B. Russell, A Critical Exposition of the Philosophy of Leibniz (1900), second edition published in 1937;} London/New York 1992, in particular ## 8, 12, 13, 107-108, pp. 11-12, 26-28, 29-35, and 203-206.

3

The most telling passage occurs in a dialogue written between 1677 and 1679, Dialogus inter Theologum et

Misosophum, where Leibniz contrasts the point of view of the ‘fideists’, i.e. of those who maintain that “human

principles cannot prove anything at all in the field of divine things [humana principia in divinis nihil certi

probare]”, i.e. question the very same compatibility between faith and reason. Against the claim that principia humana non sunt accommodata rebus divinis, Leibniz replies: “The principles of natural science, I agree, are

only human […]; but the principles of metaphysics are common to divine and human things, for they dwell with being in general, which is common to both God and creatures” (A VI 4, 2215). The idea that the notion of Ens in

genere is common to both God and creatures places Leibniz in the tradition of univocism from Scotus to Suárez.

A different reading of this passage, more inclined to read Leibniz as close to the tradition of the analogy of being, has been proposed by M. R. Antognazza, Leibniz on the Trinity and the Incarnation. Reason and

Revelation in the Seventeenth Century, New Haven/London 2007, p. 69. For a discussion of Leibniz’s different

ways of combining analogy and univocity, see also G. Grua, Jurisprudence universelle et théodicee selon

(12)

3 between analysis and synthesis. Therefore, he is able to conclude that Leibniz’s alleged belief that existential propositions are synthetic ones has to be regarded as a sort of ancestor of Kant’s thesis that existence cannot be a reality but has to be understood as the absolute position of a thing with all its predicates (from which the rejection of the ontological argument directly follows).

Russell’s reading, as is well-known, moves from the analysis of the proposition. This holds also in the case of his analysis of the notion of existence, which is dealt with moving from the distinction between necessary and contingent propositions:

“Contingent propositions, in Leibniz’s system, are, speaking generally, such as assert actual existence. The exception which this statement requires, in the case of the necessary existence of God, may be provided for by saying that contingent propositions are such as involve a reference to parts of time. […] Thus necessary propositions are such as have no reference to actual time, or such as –except in the case of God –do not assert the existence of their subjects. […] But propositions about contingency itself, and all that can be said generally about the nature of possible contingents, are not contingent; on the contrary, if the contingent be what actually exists, any proposition about what might exist must be necessary”.4

The main idea is that, for Leibniz, every proposition should be reduced to the attribution of a predicate to a subject, with the only exception of existential ascriptions. This follows from Leibniz’s claim that all the properties of an individual (i.e. all the properties an individual substance will display over time) can be derived or deduced from the complete concept of that individual, for they are already contained or involved (in a non-temporal way) therein. This is just Leibniz’s conceptual containment theory of truth. The only exception to the conceptual containment theory concerns actual existence: “Existence alone, among predicates, is not contained in the notions of subjects which exist. Thus existential propositions, except in the case of God’s existence, are synthetic […]”.5

This is the only way of safeguarding the contingency of existing things; otherwise, if we assume that existence is just a predicate as the other ones, it must be contained in the complete notion of the individual, and, therefore, it must be analytically derivable from it. Given the (Kantian) identification between analyticity and necessity, it would follow that all things exist necessarily.6 (Notice, however, that the identification of ‘analytic’ and ‘necessary’ is already at work in Arnauld’s first objections to Leibniz). This immediately leads to the first corollary of Russell’s view, i.e. that existence is the only contingent feature an individual may have.

It is important to stress that Russell is talking of actual existence alone, and this restriction is fundamental in order to fully understand the point raised by Russell in the passage above. He states, indeed, that necessary truths are those that have no reference to actual time or do not assert the actual existence of their subjects. This notion of necessity, however, holds not only

4

Russell, The Philosophy of Leibniz, # 13, pp. 29-30. 5_{Ibid., # 8, p. 11.}

6_{Cf. Ivi: “Necessary propositions are such as are analytic, and synthetic propositions are always contingent”.} The relevance of the book on Leibniz for the understanding of Russell’s philosophy has been discussed by N. Griffin, “Russell and Leibniz on the Classification of Propositions”, in R. Krömer-Y. Chin-Drian (eds.), New

Essays on Leibniz Reception in Science and Philosophy of Science 1800-2000, Basel 2012, pp. 84-125. For a

more historically-oriented reconstruction of the sources and the genesis of Russell’s book, see W. O’ Briant, “Russell on Leibniz”, Studia Leibnitiana, 11, 2, 1979, pp. 159-222. On Russell’s philosophical background in the period when he wrote the book on Leibniz, see M. Di Francesco, Il realismo analitico. Logica, ontologia e

(13)

4 in the case of general propositions concerning specific essences (or incomplete notions), like mathematical propositions or essential truths like ‘All the men are animal’, where genus is predicated of a species, but it holds in the case of those propositions that predicate a species of a particular individual as well. This is what Russell has in mind when he notes that propositions about contingency itself (i.e. about what might exist) are not contingent, for contingency should be ascribed to actual existence alone.7 Therefore, all truths about possibles are necessary (or, alternatively, whatever is possible, is necessarily so).8

Leibniz, according to Russell, would have thus anticipated the Kantian distinction between “the notion of an existent and the assertion of actual existence”:

“The notion of an individual, as Leibniz puts it, involves reference to existence and time sub ratione

possibilitatis [think, for simplicity, of the eternalized version of a tensed proposition, like “Alexander the

Great died in 323 BC”, which is eternally true], i.e. the notion is exactly what it would be if the individual existed, but the existence is merely possible, and is not, in the mere notion, judged to be actual”.9

This sort of ‘splitting’ of existence into actual and possible one is a remarkable point, which will be recalled many times in what follows. For the moment, I want just to insist that Leibniz’s idea that the possibility of individuals (and truths about contingent facts) differ from the possibility of species –for the former (but not the latter) involve in their notions the possibility of their causes –is not taken by Russell as sufficient to conclude that Leibniz succeeded in placing contingency within the complete concept itself, but, rather, as a sort of parallelism between the domain of the possible and that of the actual. For the connections between possible causes and possible effects is similar to that between actual causes and actual effects; and the latter is based on the former (for the possibility of things precede their actuality, at least from God’s point of view).

Therefore, “so long as we do not assert actual existence, we are still in the region of eternal truths”. Contingency properly said, indeed, obtains only with the passage to actuality:

“It is in taking the further step, in judging the actual existence of the individual whose notion is in question, that the law of sufficient reason becomes indispensable, and gives results to which the law of contradiction is, by itself, inadequate […]. Existence is thus unique among predicates. All other predicates are contained in the notion of the subject, and may be asserted of it in a purely analytic judgment. The assertion of existence, alone among predicates, is synthetic, and, therefore, in Leibniz’s view, contingent. Thus existence has, for him, just as peculiar a position as it has in Kant’s criticism of the ontological proof, and it must be regarded as a sheer inconsequence, in Leibniz, that he failed to apply this doctrine also to God. But for the fact that Leibniz

7_{Referring to Leibniz’s discussion with Arnauld (see GP II, 39), where the former explains that the notion of a} species involves only necessary truths while the notion of an individual involves (sub ratione possibilitatis) what is related to the existence of things and time, Russell points out that even propositions concerning individuals and those features which we take as existence-entailing (as spatiotemporal location, causal connections, and so on) must be taken (sub ratione possibilitatis) as eternally true or false.

8_{Being still committed to a (lato sensu) Kantian understanding of modality, Russell took that claim as equivalent} to the idea that truths about the possibles are eternally true. Still in his 1918 lectures on the philosophy of logical atomism, Russell maintains the view that modality can be ascribed to propositional functions (i.e. concepts) only, and not to things, and that modality has to be interpreted in a temporal way (for instance, a propositional function is necessary if it is always true). Cf. B. Russell, The Philosophy of Logical Atomism (1918), Oxford 2009, pp. 64-5.

9

(14)

5 definitively asserted the contrary […], one would be tempted to state his position as tantamount to a denial that existence is a predicate at all”.10

1.2 Russell between Leibniz and Kant

Russell’s hesitation to ascribe a full-fledged Kantian view to Leibniz is also due to the fact that, in a passage from the New Essays (as well as elsewhere), Leibniz explicitly treats existence as a notion or an idea that is predicated of a subject into a proposition.11

Russell’s conclusion, however, can be defended by a direct reference to Kant himself.

At the beginning of his 1763 essay on The only Possible Argument in support of a Demonstration of the Existence of God, indeed, the claim that “Existence is not a predicate or a determination of a thing” is defended in the following way:

“Take any subject you please, for example, Julius Caesar. Draw up a list of all the predicates which may be thought to belong to him, not excepting those of space and time. You will quickly see that he can either exist with all these determinations , or not exist at all. The Being who gave existence to the world and to our hero within that world could know every single one of these predicates without exception, and yet still be able to regard him as a merely possible thing which, in the absence of that Being’s decision to create him, would not exist. Who can deny that millions of things which do not actually exist are merely possible from the point of view of all the predicates they would contain if they were to exist. Or who can deny that in the representation which the Supreme Being has of them there is not a single determination missing, although existence is not among them, for the Supreme Being cognises them only as possible things. It cannot happen, therefore, that if they were to exist they would contain an extra predicate; for, in the case of the possibility of a thing in its complete determination, no predicate at all can be missing”.12

Few pages below, Kant employs the same metaphor once again, in order to give more strength to his metaphysical thesis:

“If I imagine God uttering His almighty ‘Let there be’ over a possible world, He does not grant any new determinations to the whole which is represented in His understanding. He adds no new predicate to it. Rather, He posits the series of things absolutely and unconditionally, and posits it with all its predicates; everything else within the series of things is posited only relatively to this whole”.13

Reference to God’s positing the whole series of things (i.e. the whole world) “absolutely and unconditionally” is just another way of saying that actual existence is the absolute position of a thing with all its predicates, to be contrasted with the relative position in which the relation

10_{Ibid., # 13, pp. 31-32.} 11

Cf. New Essays, IV, i, 3, A VI 6, 358: “When we say that a thing exists, or has real existence, this existence itself is the predicate, i.e. it has a notion joined to the idea in question, and there is connection between these two notions” (I follow Russell’s own translation here). Other passages which speak in favour of existence as a predicate will be discussed in Chapter 8 below. Not all of them had been published when Russell wrote his book. This is one of the reasons why, later on, he rejected his original position after the publication of Leibniz’s unpublished works by Couturat (see below).

12_{Kant, On the only Possible Argument in support of a Demonstration of the Existence of God, 1763, Ak. II, 72;} translated in I. Kant, Theoretical Philosophy 1755-1770, edited by D. Walford and R. Meerbote, Cambridge 1992, pp. 117-18.

13

(15)

6 between the logical predicate and the logical subject are related in a proposition. The extra-propositional and positional character of existence, therefore, is clearly stated by Kant within a ‘possible worlds’ framework which is very close to that adopted by Leibniz.

Paradoxically as it might be, indeed, both these Kantian passages (reference to God’s fiat included) are nothing but a quotation of similar passages in the Theodicy, like the following one:

“Since […] God’s decree consists solely in the resolution he forms, after having compared all possible worlds, to choose that one which is the best, and bring it into existence together with all this worlds contains, by means of the all-powerful word Fiat, it is plain to see that this decree changes nothing in the constitution of things: God leaves them just as they were in the state of mere possibility, that is, changing nothing either in their essence or nature, or even in their accidents, which are represented perfectly already in the idea of this possible world”.14

The similarity between this passage and the Kantian ones are striking, also because all the elements that lead Kant to conclude that existence is an absolute position are already contained in what Leibniz says, i.e. that God’s decision to create something is a ‘global’ (or ‘holistic’) one, for he brings to existence a thing together with the world it belongs to; moreover, God’s decree (his fiat) changes nothing in the constitution of things from the way they are represented “in the state of mere possibility”.

The main difference, however, is that Leibniz does not conclude that existence is the absolute position of a thing with all its predicates, even though this seems to be implicit in what he says. Furthermore, contrary to Russell’s corollary above, Leibniz’s aim in this passage is that of conciliating a strong determinism concerning the succession of things and events in the world (and God’s foreknowledge thereof) with the distinction between necessary and contingent properties.

The fact that God can change nothing in the constitution of things, indeed, is stressed by Leibniz in order to conclude that God cannot decide what belongs to a thing essentially or accidentally, but that this very same distinction is already established at the level of mere possibility. This is confirmed by the conclusion of the passage: “Thus that which is contingent and free remains no less so under the decrees of God than under his prevision”.15

I shall come back to this tension between ‘necessity of essences’/ ‘contingency of existence’ on one hand, and the maintaining of the ‘essential’/ ‘accidental’ distinction as internal to any series of things on the other hand.

1.3 Russell and Couturat on Conceptual Containment and Existence

14_{Theodicy, # 52, GP VI, 131 /H 154-55. Kant’s acquaintance with the Theodicy dates back at least to 1753,} when he was working to an essay (which he will never complete, ultimately) for the prize-essay competition of the Academy of Berlin devoted to a comparison of Leibnizian optimism with that of Pope. Cf. Kant’s unpublished reflections, nn. 3703-5, Ak. XVII, 229-39, as well as his brief 1759 paper, An Attempt at Some

Reflection on Optimism, Ak II, 27-35; both these texts are translated in Theoretical Philosophy, pp. 77-83 and

67-76. On the reception of Theodicy in Germany, cf. S. Lorenz, De mundo optimo. Studien zu Leibniz’

Theodizee und irher Rezeption in Deutschland (1710-1791), Steiner 1997.

15

(16)

7 The core of Russell’s analysis in 1900 may be summarized as follows: (1) actual existence is the only contingent feature one can ascribe to an individual thing according to Leibniz; (2) all truths concerning possible things are necessary. The first point amounts to acknowledge an exception for the predicate-in-subject account of truth (conceptual containment).

The latter point, however, will be reconsidered by Russell after 1903, i.e. after the publication of Couturat’s works on Leibniz’s logic (in 1901) and his edition of Leibniz’s unpublished papers (in 1903). This change of mind already appears in Russell’s 1903 review to Couturat’s works in a paper published on Mind, and will be repeated in the preface Russell appointed to the new edition of his book published in 1937.

In particular, against Russell’s original claim, Couturat challenged the tenability of the (Kantian) distinction between analytic and synthetic propositions, for all propositions (existential ones included) have to be taken as analytic ones insofar as they might be derived (at least from God) from the account of truth based on conceptual containment.16 Notice, however, that, as far as existence is concerned, Russell did not completely accept Couturat’s account, for, while the latter is substantially committed to the idea that existence is a property analytically derivable from the concept of a thing (via the notion of perfection), Russell still believes there is a considerable tension between this line of thought (which he now takes as being more preponderant than what he originally believed in 1900) and the opposed one, according to which it is impossible to find something more in the concept of an existing thing than in that of the corresponding possible one, i.e. what throughout this work I dub as the ‘puzzle of existence’.17

2. The Superessentialist Account: Existence as Concept-Instantiation

If I have insisted so much on Russell’s views is only because I am convinced that much of the following debate about existence and contingency in Leibniz is (to recall Whithead’s famous quotation) just a sort of footnote to Russell; or, better said, it might be summarized as the contraposition between a Neo-Russellian view and an anti-Russellian one. This is particularly true so far as the debate concerning Leibniz’s superessentialism is taken into account. The superessentialist position, indeed, can be legitimately conceived of a sort of continuation and enforcement of Russell’s original research program.

16_{In particular, Couturat emphasized the possibility of deriving the whole set of Leibniz’s metaphysical theses} from the conceptual containment account of truth as presented by Leibniz himself in his unpublished texts on “Primary Truths”, edited for the first time by Couturat himself. Cf. in particular, L. Couturat, “Sur la métaphysique de Leibniz (avec un opuscule inédite)”, Revue de Métaphysique et de Morale, 10, 1, 1902, pp. 1-25 (the unpublished text called by Couturat Primae Veritates has been published now in A VI 4, 1643-49, under the title Principia logico-metaphysica). For Russell’s reading of Couturat on Leibniz, see B. Russell, “Recent Work on the Philosophy of Leibniz”, Mind, 12, 16, 1903, 177-201; and the 1937 preface to the book on Leibniz, cf. “The Philosophy of Leibniz”, pp. xiii-xviii.

17_{Cf. Russell, “Recent Work”, p. 185. An attempt to make sense of this apparent opposition, and to defend} Russell’s original claim (that existence is not included in the complete concept of a thing), has been proposed by E. Curley, “The Root of Contingency”, in H. Frankfurt (ed.), Leibniz. A Collection of Critical Essays, London 1976, pp. 69-97 (cf. my discussion in Chapter 8 below). For a contemporary ‘Leibnizian’ approach to the puzzle of existence, see N. Rescher, The Riddle of Existence. An Essay in Idealistic Metaphysics, Lanham MD 1984; Id., On Explaining Existence, Berlin 2013.

(17)

8 In the period between Russell’s book and the recent times, however, something else happened in the Leibniz-scholarship. I am not referring just to the publication of many texts which were unknown to both Russell and Couturat (and which shed new lights on many aspects of Leibniz’s philosophical development), but of a new interpretative key that led many scholars to a reappraisal of Russell’s original intuitions. I am thinking of the renewed interest in Leibniz’s metaphysics of possible worlds, essentially motivated by the exploit of the ‘possible-worlds semantics’ after Kripke’s seminal works in the 60’s and the applications of the latter to the field of modal metaphysics.18

The main difference with Russell’s analysis, indeed, is that the examination of necessity and contingency is now explicitly framed into a possible-worlds account rather than based on a Kant-style distinction between analytic and synthetic truths.19 Even though Russell himself did not completely disregard the idea that, for Leibniz, necessary truths are those which are true of every possible world, his own favourite reading was by far that which connected the notion of ‘necessity’ with that of ‘analyticity’.20

The superessentialist reading (as defended in the works of B. Mates and F. Mondadori), on the contrary, is essentially committed to the claim that Leibniz (implicitly or explicitly) envisaged the idea that the contraposition between necessity and contingency has ultimately to be understood as one between those truths which hold at (are true of) every possible world and those truths which hold at (are true of) some of them. In the following, for the sake of simplicity, I will take into account just two paradigmatic opposite views, i.e. the superessentialist reading provided by Mates and contrast him with the ‘contingentist’ one provided by R. M. Adams (for the latter is explicitly intended as opposed to the former).21

18

For a good summary, see Loux’s introduction (“Modality and Metaphysics”) to M. J. Loux (ed.), The Possible

and the Actual. Readings in the Metaphysics of Modality, Cornell University Press 1979, pp. 15-64. On Leibniz, see B. C. Look, "Leibniz's Modal Metaphysics", The Stanford Encyclopedia of Philosophy (Spring 2013 Edition), Edward N. Zalta (ed.), URL = https://plato.stanford.edu/archives/spr2013/entries/leibniz-modal/. 19

No such a distinction can be found in Leibniz’s main texts. A partial exception might be represented by a remark in his late Notes on Temmik, where he writes: “Predicates may be distinguished in those which add something to a subject, and those which add nothing to it. In this way, ‘rationality’ or ‘capacity of being marvelled’ add nothing to the concept of ‘man’. On the contrary, ‘learnedness’ adds something on the basis of which a man is said to be learned. Should we say that ‘paternity’ adds something to Philip? If individuals are taken as complete notions, it adds nothing at all. One can say that contingent predicates are essential to individuals, for it is proper of an individual notion to include all contingent predicates. But contingent predicates are not essential to every individual whatever, at least those which do not exhaust his whole power [vim]” (Notationes quaedam ad Aloysii Temmik Philosophiam, published in M. Mugnai, Leibniz’s Theory of Relations, p. 156).The distinction between predicates which add and those which do not add something to a concept might resemble the Kantian distinction between synthetic and analytic predicates (the former enlarge a concept, the latter only explains what is already contained in it). Notice, however, that such a distinction holds only in the case of general concepts, like ‘man’, where ‘rationality’ can be take to be analytic since it is contained in the definition of ‘man’, whereas ‘learnedness’ is not (the former stands for an essential property, the second for a contingent one). When coming to individual notions, i.e. complete notions, even contingent properties are to be regarded as ‘analytic’, i.e. they add nothing to the concept (otherwise it would not be a complete one, after all). Contingent predicates are essential to individuals, and only accidental to general notions (specific concepts). 20_{Cf. Russell, The Philosophy of Leibniz, # 12, pp. 26-28, especially where Russell remarks that Leibniz’s claim} that a necessary proposition is one the opposite of which involves a contradiction is not a definition of ‘necessity’. In order to avoid the conclusion that necessity is ultimately an indefinable and primitive notion, he resorts to analyticity (note that, at that period, Russell still accepted the Kantian idea that mathematical propositions are necessary and synthetic, whereas he will abandon this view when he will develop his ‘logicist’ account, as he himself recognizes in the preface to the second edition).

21_{Cf. B. Mates, “Leibniz on Possible Worlds”, in B. Van Rootselaar- J. F. Staal (eds.), Logic, Methodology, and}

(18)

9

2.1 Predicates or Properties?

In order to understand in which sense Mates’ reading can be regarded as a ‘radicalization’ of Russell’s views, however, some preliminary remarks are in order. Together with ‘possible-worlds semantics’, indeed, the fundamental passage to understand the superessentialist reading of Leibniz is its connection with a logical/philosophical account of existence, one defended by Russell himself in his theoretical works written after the book on Leibniz.

In the previous paragraph, indeed, I have stressed the fact that Russell (in 1900) still framed the question of existence in terms of the question whether existence is a ‘predicate’ or not. In the contemporary debate, however, the main question is whether existence might be regarded as a property of individuals or not.

The distinction between properties and individuals is usually introduced by means of the notion of ‘instantiation’ (or, alternatively, ‘exemplification’): whereas individuals instantiate properties and cannot be instantiated by anything else, properties can only be instantiated by individuals or by other, less general, properties. The question whether existence is a property of individuals or not, therefore, amounts to ask whether ‘existence’ corresponds to a property that a determinate individual (say, Alexander the Great) instantiates or not; and, eventually, whether there are also individuals lacking that property, i.e. merely possible or fictional ones.22

The passage from talking of ‘predicates’ to talking of ‘properties’ might be regarded as an innocuous one, at least if one assumes that there is a one-to-one correspondence between predicates (on the linguistic level) and properties (on the ontological one). The latter view is the so-called abundant conception of properties, which is usually contraposed to the sparse one. If one accepts the first view, since ‘existent’ is a linguistic predicate, then also the view that existence is a property of individuals must be accepted. At the linguistic level (at least, at the level of natural language), no one doubts that ‘existent’ behaves like any other ordinary predicates. There are reasons to doubt of such a perfect match between the linguistic and the ontological level.23

From Leibniz point of view, at least, the abundant conception of properties conflicts with the claim that there are no such things like purely extrinsic denominations, i.e. properties which “Individuals and Modality in the Philosophy of Leibniz”, Studia Leibnitiana, 4, 1972, pp. 81-118; Id., The

Philosophy of Leibniz. Metaphysics and Language, Oxford 1986; R. M. Adams, “Leibniz’s Theories of

Contingency”, in M. Hooker (ed.), Leibniz. Critical and Interpretive Essays, Minneapolis 1982, pp. 243-83; Id., Review of B. Mates, “The Philosophy of Leibniz”, Mind 97, 1988, pp. 299-302; Id., Leibniz. Determinist. Theist.

Idealist, New York/Oxford 1994.

22

My account is substantially based on M. Nelson, "Existence", The Stanford Encyclopedia of

Philosophy (Winter 2016 Edition), Edward N. Zalta (ed.), URL =

https://plato.stanford.edu/archives/win2016/entries/existence/ . I have also taken into account F. Berto, Existence

as a Real Property. The Ontology of Meinonghianism, Dordrecht 2012; F. Orilia, Ulisse, il quadrato rotondo e l’attuale re di Francia, Pisa 20052_.

23

Discussing Leibniz’s account of relations, Mates observes that Leibniz “would not be inclined to accept every open sentence with a free variable as expressing an attribute” (“Leibniz on Possible Worlds”, p. 352). On this point, cf. also H. Ishiguro, Leibniz’s Philosophy of Logic and Language, second edition, Cambridge 1990, pp. 123-26, who discusses the difference between Leibniz’s grammatical characterization of attributes and predicates, and the metaphysical one.

(19)

10 are not grounded in some intrinsic (or qualitative) property of a thing. If one accepts the abundant conception of properties, indeed, then existence could be reduced to a merely extrinsic property, or, as we would say, to a ‘Cambridge-property’ (i.e. a property whose instantiation by the subject a does not involve a real change or a qualitative/intrinsic modification in a itself), which would provide a solution to the puzzle of existence (and would also restore the symmetry between existence and non-existence, since it is difficult to state that non-existence is a real property).

This, however, would amount to deprive existence of both its absoluteness and its reality, which would be highly counterintuitive. First, because the difference between what exists and what is merely possible should not be regarded as a merely relative one;24 second, because there is a sense in which one would say that actual existence corresponds to what is real in a thing, to the effect that to exist seems to be the main presupposition for the very same instantiation of properties (this is the original meaning of the traditional dictum: non entis

nulla sunt attributa).25 In other words, if one accepts the idea that not everything is actual (as

Leibniz does), it would unacceptable for him to state that actual existence is neither a real nor an absolute property (in the sense specified above).

This is enough to place Leibniz on the side of the sparse conception of properties, since, according to the latter, a predicate stands for a property only if the objects which the predicate is truly predicated of resemble one another in some intrinsic way. The idea that existence has to be somewhat grounded in the nature of a thing, or, better, in the degree of reality or perfection of a thing, indeed, is essentially motivated by the fact that existence cannot be considered as a merely extrinsic denomination (since there are none).26

At the same time, however, the fact that existence shares many features of extrinsic denominations, i.e. of relational properties, cannot be denied, for the maximum of perfection can be determined only through a comparison between all possible worlds (each one having its own degree of reality or perfection), and the very same notion of comparison involves a relational element. Furthermore, the (partially) extrinsic character of existence is required because, otherwise, if existence would be just an intrinsic denomination of individuals (and worlds), the actualization of the most perfect would be an automatic process, and what exists would exist necessarily. In Leibniz’s own terms, to involve the maximum degree of perfection is a necessary but not sufficient condition for an individual (a world) to be actualized, for the other element to be required is God’s decision to create (only) the best.

Paradoxically as it might be, therefore, Leibniz must find a way to conciliate the relational or partially extrinsic character of existence with the absoluteness (i.e. non relativity) of existence

24

Relativity of actual existence (actuality), if not of existence at all, is the main feature of the indexical theory defended by D. Lewis. On Leibniz’s reasons to reject the indexical theory, see Chapter 7 below.

25_{It is true that, endorsing the view that non entis nulla sunt attributa, Leibniz interprets ‘Entity’ as ranging over} possible rather than over actual things only, but the point is how to interpret the ascription of properties to non-existing things.

26

This is clear from what Leibniz says at Cout. 9 (“The category of relations such as quantity and position do not constitute intrinsic denomination themselves, and what is more, they need a basis taken from the category of quality, or intrinsic denomination of accidents”), and has been emphasized by Curley, “The Root of Contingency”. See my discussion in Chapter 8 below. For the thesis that there are no purely extrinsic denominations, see also Chapter 6 (where I discuss the theory of universal connection).

(20)

11 itself; a result that, ultimately, can be achieved only by resorting to God (to what he calls the moral necessity of creating the best).27

In what follows, therefore, I will frame the question of existence in terms of whether it might be regarded as a property of individuals (a first-order property) or as a property of concepts (a second-order property), where the first has to do with the instantiation of a property by an individual, the second with the instantiation (or the instantiation, in the case of non-existence) of a concept. The second view is commonly known as the Frege-Russell theory of existence.28

2.2 The Superessentialist Framework: Descriptivism and the Limits of Conceptual Containment

The superessentialist account defended by Mates can be regarded as coherent defence of the idea that existence has to be taken as a property of concepts, even though not of general but of individual ones, i.e. complete concepts. The sense in which this account might be regarded as ‘Russellian’ is that applied the descriptivist account (defended by Russell in 1905 and after) to the case of Leibniz’s theory of complete concepts.

The basis of the superessentialist account is the conjunction of Leibniz’s theory of complete individual concepts (the idea that “the nature of an individual substance or of a complete being is to have a notion so complete that it is sufficient to contain and to allow us to deduce from it all the predicates of the subject to which this notion is attributed”)29 with a modal characterization of essential properties. Given an individual a and a property φ, φ is essential to a if a cannot cease to instantiate φ while still existing, or while still being the same individual; in other words, if it is impossible that a exists without being φ. This modal characterization is immediately interpreted in terms of possible worlds: there are no possible worlds in which a exists and is not φ. Since all the properties of an individual are derivable from its complete concept, and the complete concept stands for the individual essence of that individual, all the properties of an individual are to be taken as essential to it.30

This conclusion follows only if one accepts an apparently bizarre thesis concerning individuation, i.e. that each individual is individuated by all its properties (where the more complicate questions concerns the status of relational ones, i.e. if relational properties have to be included into the complete notion or not). Leibniz’s theory of complete concepts, however, can be regarded exactly as the expression of such theory of individuation.

What I am interested in, however, is only the modal consequences of this view, i.e. the conclusion that since no individual exist at more than one (and only one) possible world, and

27_{This point (together with the other, very controversial one, i.e. the existence of something like the best} possible world) is what makes me sceptical about the possibility of reading Leibniz’s account of existence in terms of a purely secular metaphysics, i.e. in terms of the contemporary debate on metaphysics. A theological ground is ultimately required in order to preserve the contingency of what exists; and, after all, Leibniz himself never rejects the idea that metaphysics has to be regarded as ‘rational theology’.

28_{Cf. B. Russell, “On Denoting”, Mind, 14, 1905, pp. 479-93; Id., The Philosophy of Logical Atomism, part five} (“General Propositions and Existence”), pp. 61-77. On Frege’s position, see below.

29

Discourse on Metaphysics, # 8, A VI 4, /AG 41.

30_{This seems to derive from what Leibniz says in a text to Arnauld, cf. GP II, 53: “[…] if, in the life of any} person, and even in the whole universe, anything went differently from what it has, nothing would prevent us from saying that it was another person or another possible universe that God has chosen. It would then indeed be another individual”. Cf. also GP II, 42, with the example of the marble block.

(21)

12 all the properties of an individual have to be taken as essential to him (according to the previous characterization), it follows that all the properties of an individual (or, better, all his first-level properties) are necessary. The view follows that there is no room for contingency within the complete concept of an individual.31

As in the case of Russell’s original views, then, the necessary character of truths about possible things as possible (i.e. complete concepts before the creation of the world, so to say) makes the pair with the idea that actual existence is the only contingent feature an individual can have and, therefore, it has to be extruded from the domain of those properties which are included in the complete notion. This amounts to posit a limitation to the theory of conceptual containment.

This is exactly what happens with Mates’ reading of Leibniz. His idea, indeed, is that the predicate-in-subject containment works as a definition of truth in the full sense, i.e. as a necessary and sufficient condition for the truth of a proposition, only in the case of essential propositions. In the case of existential propositions (where quantification is restricted to what actually exists only), Mates says that “Leibniz clearly does not regard the inclusion of the predicate in subject as a sufficient, nor perhaps even as a necessary, condition of truth”.32 In the case of singular existential propositions , in particular, it works as a necessary-but-not-sufficient condition.33

2.3 Species and Individuals. A neglected Russellian remark

An interesting point in Mates’ reading is that he ascribes the idea that conceptual containment is a necessary and sufficient condition for all truths to a confusion between “containment in the general concept itself with containment in the individual concept of every existent individual falling under the general concept”. According to Mates, this sort of confusion can be ultimately reduced to a more general confusion between ‘inherence’ and ‘predication’, as it emerges from the fact that a proposition like ‘A is B’ (which, for Leibniz, means ‘Every A is B’) is sometimes interpreted as if the subject is A, and sometimes interpreted as saying that everything which is A is also B, where, however, the concept of the individual (the thing which is both A and B) is not clearly distinguished from the individual itself. 34

Also this idea, notice, might be regarded as a development of a series of intuitions originally expressed by Russell. Russell, indeed, pointed out that the subject-predicate propositions

31

This view has been clearly summarized by Rescher, who, criticizing Adams, concludes that “there are no contingent truths about possibles as such […]. Relationships among possibilities do and must play out in the thought of God sub ratione possibilitatis independently of (and so, figuratively speaking, antecedently to) his creation choice” (N. Rescher, “Contingentia Mundi. Leibniz on the World’s Contingency”, originally published in Studia Leibnitiana 33, 2002, pp. 145-62; now in Id., On Leibniz, expanded edition, Pittsburgh 2013, p. 91, note 34. As the reader can see, this is nothing else than point (2) of my summary of Russell’s views above. The same idea, that the independency of possibles from God’s will amounts to say that truths about possibles are necessary has been defended by Mates, Mondadori, and many others.

32

Mates, The Philosophy of Leibniz, p. 87. The distinction between the essential and the existential reading of propositions has been stressed also by H. Ishiguro, Leibniz’s Philosophy of Logic and Language, second edition, Cambridge 1990, pp. 183-87. I discuss Leibniz’s distinction in the GI and elsewhere in Chapter 9 below. 33_{Cf. Mates, The Philosophy of Leibniz, p. 86.}

34

(22)

13 involve two different kinds of relations, i.e. that between genera and species and that between species and individuals, which Russell exemplified as ‘Red is a colour’ and ‘This is red’. When dealing with the doctrine of conceptual containment, Russell pointed out that the doctrine works with propositions of the genera-species kind, i.e. like ‘Red is a colour’, and not with propositions of the kind ‘This is red’ (or ‘Socrates is human’), and, for Russell, this is also the main reason why every proposition about actual individuals is contingent (which, for him, means they are synthetic).35

This, however, seems to posit a problem in the case of essential propositions concerning individuals, or, if you prefer, propositions concerning non actually existing individuals. For, if, as Russell maintains, “analytic propositions are necessarily concerned with essences and species, not as with assertions as to individuals”, the difference between the individual and his properties, which holds at the level of what is actual, goes completely lost at the level what is merely possible.

On this point, Russell makes two observations. The first is that, if reference to individuals is essential to the distinction between subject and predicate, one must conclude that the subject is “any individual having a certain collection of predicates”. Therefore, propositions of the type genera-species must be reduced to those of the type species-individuals, i.e. by transforming the former into hypothetical propositions, which, in effect, is the strategy Leibniz suggests in a famous passage of the New Essays.36 This reduction, according to Russell, fails because Leibniz assumes that hypothetical truths have no existential import, i.e. they do not assert the existence of their subjects, and, indeed, Leibniz “goes on to say that the truth of hypothetical propositions lies in the connection of ideas”, i.e. on conceptual containment again.37

The second interesting point raised by Russell (a point on which I will insist in the following) is that there is a sort of tension, in Leibniz’s system, between a line of thought which moves from essences and arrives (or aims to arrive) to the individuals, and another one which, on the contrary, moves from individuals and arrives to predicates and essences.38 Whereas, in the case of eternal truths, we start with essences and predicates, and their mutual relations, in the case of contingent truths, the point of departure is given by the existing individual and the relations between individuals.

In what follows, I will show how these two strands in the philosophy of Leibniz correspond to two different philosophical views, one closer to traditional essentialism, and the other closer to the nominalist tradition. The point where these two views should find a connection is represented by the idea of ‘possible individuals’, whose problematic aspect is given by their sharing with what is actual many important properties (i.e. all those properties we normally take as existence-entailing: relations of connection, spatiotemporal location, causal connections, and so on), but not actuality.

A corresponding contraposition occurs in the debate on the notion of existence, between those who hold the Russellian view, where, substantially, the extra-propositional character of

35

Cf. Russell, The Philosophy of Leibniz, #11, p. 20. 36_{Cf. New Essays,}

37_{Russell, The Philosophy of Leibniz, # 11, p. 21. Cf. also # 21, p. 58, where he states that the kind of} subject-predicate propositions appropriate to contingent truths is that which says “This is a man”, not “Man is rational”. 38

Modality, ontology, and phenomenology : Leibniz’s multiple views on existence : a historical and analytic reconstruction

Scuola Normale Superiore di Pisa

Modality, Ontology, and Phenomenology.

Leibniz’s Multiple Views on Existence

A Historical and Analytic Reconstruction

Contents

0 Introduction: The Puzzle of Existence. From Russell to

Leibniz………1

1 Section I: Between Suárez and Hobbes. Leibniz’s Account of

Existence in His Early Writings (1663-1676)

53

2 Section II: “Series rerum”. The Actual World and the Genesis

of Leibniz’s Theory of Possible Worlds ………230