1 Curley, Edwin Behind the Geometrical Method (Princeton: Princeton University Press 1988), 86;CrossRefGoogle Scholar Mateson, Wallace ‘Death and Destruction in Spinoza's Ethics,’ Inquiry 20 (1977), 404–5;Google Scholar Nadler, Steven Spinoza's Heresy (Oxford: Oxford University Press 2002), 126Google Scholar

2 Cogitata Metaphysica, Part I, Ch. VIII; G 1/264. All citations from Spinoza are from Spinoza Opera, ed. C. Gebhardt, 4 vols. (Heidelberg: Carl Winter 1925) (G hereafter). Most English translations are from Curley, Edwin ed. and trans., The Complete Works of Spinoza, vol. 1 (Princeton: Princeton University Press 1985)Google Scholar with occasional modifications. References to the Tractatus de Intellectus Emendatione are abbreviated TdlE. In citations from the Ethics, I use the following abbreviations: Roman numerals refer to parts; ‘P’ means proposition; ‘C means corollary; ‘S’ means scholium; e.g. ‘EIVP37S’ means Ethics, part IV, proposition 37, scholium.

3 EIIP7S. See also Rocca, Michael Della ‘Spinoza's Argument for the Identity Theory,’ Philosophical Review 102 (DATE??) 183–203CrossRefGoogle Scholar

4 EIIP7S

5 See n. 1 above.

6 Definition after IIP13S.

7 See Garber, Daniel ‘Descartes and Spinoza on Persistence and Conatus’, Studia Spinozana 10 [1994].Google Scholar

8 EIIL4

9 EIIL5

10 I take this example from Donagan, Alan Spinoza (Chicago: University of Chicago Press 1988), 124.Google Scholar

11 EIIL7

12 EIIL6

13 EIIL7S. See ‘What Counts as an Individual for Spinoza,’ in Koistinen, O. and Biro, J. eds., Spinoza: Metaphysical Themes (New York: Oxford University Press 2002), 89–112CrossRefGoogle Scholar for an interesting discussion of Spinoza's views on levels of individuality with a Special emphasis on the question of whether or not the State counts as an individual according to Spinoza's definition.

14 Postulate I after IIP13S.

15 Postulate IV after IIP13S.

16 IVP39.

17 Matheron, Alexandre Individu et communauté chez Spinoza (Paris: Editions de Minuit 1969), 38–40;Google Scholar Lachterman, David R. ‘The physics of Spinoza's Ethics,’ in Spinoza: New Perspectives (Norman: University of Oklahoma Press 1978), 85–6Google Scholar

18 Short Treatise on God, Man, and His Well Being, II, Preface, § 12

19 Garrett, Don ‘Spinoza's Theory of Metaphysical Individuation,’ in Individuation and Identity in Early Modern Philosophy, Barber, Kenneth F. and Garcia, Jorge J.E. eds. (Albany: State University of New York Press 1994), 82–5Google Scholar

20 PPII, P22 and Cl

21 Don Garrett, ‘Individuation,’ 82-5. For evidence that Spinoza does in fact endorse the Cartesian laws of motion see Letters 6 and 13. Spinoza does, it is true, express reservations about Cartesian physics in Letters 81 and 83, but there it seems his main concern is with whether the essence of matter is Cartesian extension and whether the diversity of material things can be deduced from it and not with specific laws of motion.

22 Matheron gives the following examples. In running, the muscles are stimulated and the brain is dulled. In drunkenness, the opposite holds (Individu, 44).

23 Lemma 5, Lemma 6, Lemma 7, Lemma 7S after IIP13S

24 Caesar, De Bello Gallico, VI, 9Google Scholar

25 Pliny, Naturalis Historia, VII, 63Google Scholar

26 I owe this point to Charles Larmore.

27 E.g. Topics, VI, 1, 4.

28 This usage is infrequently remarked upon, but, for example, in Metaphysics B, 996b5-10, Aristotle writes: ‘For it is possible for all the types of causes to pertain to the same thing. A house, for example, has a source of change (the skill, the builder), a that-for-for-the-sake-of-which (its function), matter (earth and stones), and its form (its logos)’ (trans. Arthur Madigan SJ [Oxford: Oxford University Press 1999]).

29 In saying that Spinoza's mature view of ratio is not that of a numerical proportion between total motion and total rest of an individual, I do not mean to suggest that the structure or architecture of an individual cannot be described mathematically. I suspect that Spinoza thinks that it can be given a mathematical formulation (at least under the attribute of extension). I simply mean that the particular form of the mathematical description (if in fact there is one) cannot be the simplistic ratio that Spinoza describes in the Short Treatise.

30 On this point I'm in agreement with Rocca, Michael Della ‘Spinoza's Metaphysical Psychology,’ in The Cambridge Companion to Spinoza, Garrett, Don ed. (Cambridge: Cambridge University Press 1995), 206–10.Google Scholar

31 Of course there is gravitational attraction, but, for pebbles at such distances, it is negligible. Where do we draw the line between negligible and non-negligible interactions? Clearly the concept of motions being systematically related is a vague one. Consequently, any concept of complex individuality built out of it will inherent its vagueness.

32 Cf. Della Rocca, 201.

33 Despite its prima facie plausibility, Spinoza's account is, unfortunately, vulnerable to counterexamples. For example, if two men are joined together with superglue, their motions will become systematically related and that relation will have a tendency to persist. But they will not have joined to constitute a Single complex individual.

34 Cf. Lycan, William ‘The Trouble with Possible Worlds,’ in The Possible and the Actual, Loux, Michael J. ed. (Ithaca: Cornell University Press 1979), 291–2.Google Scholar

35 EIIP7

36 EU, Post. II, GII/102

37 Spinoza is committed to a ban on inter-attribute explanations (IP10). That is, no extension-involving fact can explain a thought-involving fact and vice versa. In what follows, I shall often offer what appear to be inter-attribute explanations (e.g., sense experience occurs when motions are introduced into … etc.). I do so for ease of exposition. This is, however, harmless because there is a simple recipe for transforming inter-attribute explanations into intra-attribute explanations. In order to transform an inter-attribute explanation into one wholly contained by the attribute of extension, replace every occurrence of a psychological term with an expression formed by prefixing ‘the extended counterpart of…’ to that term. For example, ‘sense experience’ becomes ‘the extended counterpart of sense experience.’ Likewise, inter-attribute explanations can be brought entirely under the attribute of though by prefixing ‘the psychological counterpart of…’ to every term referring to an extended thing. From here on out, whenever I appear to offer an inter-attribute explanation, I wish to be understood as instead stating the disjunction of the two intra-attribute explanations that result from the two applications of this recipe.

38 Definition following A2, GIII/99-100.

39 TdlE hereafter, §83

40 EIIP17CD

41 Ibid.

42 Ibid.

43 There is a condition missing from this analysis that is, in the judgment of many, a necessary condition for memory: the subject of the memory must be identical to the subject of the original experience. You cannot remember what you never experienced. This condition is never explicitly stated by Spinoza. It is, however, consistent with everything he says about memory. Perhaps he regarded it as so trivial as to hardly require explicit Statement. But see note 48 for some reasons not to include such a condition.

44 TdlE, §83

45 IEP15S and DPP 1/188

46 Definition after IIP13S

47 It is likely, but not necessary. Two complex bodies could have two distinct rationes that are nevertheless indistinguishable with respect to some non-empty set of interactions of their parts. If we were to add as a necessary condition for memory that the rememberer and the experiencer must be the same person (as was considered in note 43), then sameness of ratio would indeed be necessary condition for memory because it is a necessary condition for sameness of complex individual. However, if we were to add such a condition to our analysis of memory, we would be forced to admit that memory is not the proper topic of Spinoza's Spanish poet example, which is concerned with an individual who has no experience as of writing the poems composed by the Spanish poet. So the person is the Spanish poet case not only doesn't have memories in the factive sense, but he doesn't even have apparent memories of writing the poems.

48 Here I agree with Ablondi, Frederick and Barbone, Steven ‘Individual Identity in Descartes and Spinoza,’ Studia Spinozana 10, 84–6.Google Scholar

49 This formulation comes from Frankfurt, Harry ‘Freedom of the Will and the Concept of the Person,’ The Journal of Phüosophy 68 (1971) 5–20.Google Scholar

50 Thomas Hobbes, De Cive, 1.7. All citations of from Hobbes are from The English Works of Thomas Hobbes of Malmesbury, and Opera Latina, Molesworth, Sir William ed. (Darmstadt: Scientia Lerlag Aalen 1966).Google Scholar

51 Ibid.

52 Hobbes, Thomas Leviathan, Edwin Curley, ed. (Indianapolis: Hackett 1994), 27Google Scholar

53 Leviathan, 27-9

54 Matheron, 86-8

55 See Reid, Thomas Essays on the Intellectual Powers of Man, iii. 6, vol. 1Google Scholar of The Works of Thomas Reid, Sir William Hamilton, ed. (Edinburgh, 1872), 7th edition, 351.

56 See, for instance, Parfit, Derek ‘Personal Identity,’ Philosophical Review 80 (1971) 3–27;CrossRefGoogle Scholar Lewis, David ‘Survival and Identity,’ in The Identity of Persons, Rorty, Amélie Oksenberg ed. (Berkeley: University of California Press 1976), 17–40;Google Scholar and Shoemaker, 89-91.

57 E.g., EIVP31, 32, 33, 35, and 37Sl.

58 C.f. Curley, 17-18.

59 See IP8S quoted above.

60 IVP35, IVP35D, IVP35C1, IVP25C2, IVP35C2S

61 Steven Nadler lodges a similar criticism of Spinoza's account of personal immortality in his Spinoza's Heresy, 129-30.

62 Spinoza adheres to a version of the Principle of the Identity of Indiscernibles (or PII) according to which, if there are two things then there must be some difference between them. Versions of the PII differ over what kinds of features are eligible to distinguish distinct individuals. For example, it is common to insist that the distinguishing features must be qualitative, and sometimes it is said that they must be intrinsic. One possible response Spinoza could make to this objection is to say that the only features that are eligible to play the role of distinguishing individuals are those that determine an individual's ratio. But such a strong version of the PII is hardly plausible and seems quite ad hoc.

63 I would like to thank Donald Ainslie, Lisa Shapiro, Charles Larmore, Dan Garber, Martha Nussbaum, Michael Green, Bill Seager, Candace Vogler and two anonymous referees for many helpful comments and criticisms.