1 ‘Symposium: The Principle of Individuation,’ Proceedings of the Aristotelian Society, Suppl. Vol. 27 (1953) 69-120

2 This way of putting the point – viz., that the numerical distinctness of two individuals is due to the numerical distinctness of the parcels of matter composing them — makes it clear that Aristotle's point, if it is to be successful, cannot be to provide an analysis of the notions of numerical identity and distinctness in general. However, it would not be circular to claim that the numerical distinctness of material substances in particular is to be accounted for in terms of the numerical distinctness of their component parcels of matter.

3 We should also distinguish between strong and weak versions of the principle of individuation. The strong version will tell us what makes an individual numerically distinct from all other possible individuals; the weak verion need deal only with the question of what marks an individual off from all other actual individuals. What suffices as a weak principle of individuation may not be adequate as a strong principle. This distinction will come into play in §II below.

4 The labels are due to Montgomery Furth ('Transtemporal Stability in Aristotelean Substances,’ Journal of Philosophy 75 [1978] 624-46) although the distinction in temporal perspective can be found in a number of authors: Anscombe; Charlton, W., ‘Aristotle and the Principle of Individuation,' Phronesis 17 (1972) 239-49;CrossRefGoogle ScholarCode, Alan, What is it to be an individual?', Journal of Philosophy 75 (1978) 647-8;CrossRefGoogle ScholarHartman, Edwin, Substance, Body, and Soul (Princeton, NJ: Princeton University Press 1977), Ch. 2.Google Scholar

5 Charlton, 239

6 Charlton, cited in n. 4 above

7 So called by Kirwan, C., Aristotle's Metaphysics Books Γ, Δ, and E (Oxford: Oxford University Press 1971) 139.Google Scholar

8 Charlton, 243

9 Furth, 643

10 Ibid.

11 Charlton, 244

12 I will touch on this question in §II below.

13 I am grateful to Alan Code for pointing out this possibility to me; I thank him also for providing many helpful comments on an earlier draft of this paper.

14 Stated explicitly in Met. Z.15 (1039b26ff) and Z.10 (1036a2-8). and supported also by Z.11 (1036a28-9, 1037a28) and by Z.4 (1030a2-16).

15 I owe this felicitous way of expressing the relation between essence and definition to Alan Code. Cf. his ‘Aristotle: Essence and Accident,’ in Grandy, R.E. and Warner, R., eds., Philosophical Grounds of Rationality: Intentions, Categories, Ends (Oxford: Oxford University Press forthcoming).Google Scholar

16 Cf. Met. 1.9 (1058b10). Z.11 (1037a1-2, 1037a29). and Z.15 (1039b21).

17 As envisaged in the interpretation of 1034a5-8 that was rejected in §I above.

18 The relevance of eternality to the question is that Aristotle thinks that one objection to the notion that there can be definitions of individuals is that material individuals are typically perishable and thus not suitable definienda; but this need not detain us here.

19 It is only if we require the principle to individuate among all possible individuals that we can be forced by this argument to interpret it along traditional lines. (D), the principle I take to underlie the duplication argument, cannot rule out the possibility that, for any pair of distinct actual individuals, there is some accident that discerns them.

On the other hand, if Aristotle's interest is in individuation among possible individuals, we can see why he would not be able to appeal to the accident of spatial location to individuate. For while any distinct actual contemporaries will differ in spatial location, this need not be so for distinct possible contemporaries. (E.g., this table is not distinguishable in location from another possible table that would have been here had a different batch of lumber been used to make a table for this room.)

20 Aristotle's analogy is slightly more elaborate than this. But the simplified version presented here contains all the essential ingredients.

21 The third definition of seems to specify the sense that is relevant to Aristotle's discussion of uniqueness, and so it is the one I will consider here.

22 , 278b18-21. I have altered the wording of the definition somewhat to facilitate the discussion. I hope I have not distorted its sense.

23 The point may be put (anachronistically, to be sure) in this Kripkean way: universe can be defined by the definite description ‘the totality of matter within the celestial sphere’ so long as that description is understood to be a non-rigid designator. But ‘this universe’ is a rigid designator, and so cannot be defined in the same way.

24 I am assuming that it is the presence of the indexical ‘this’ in the description ‘the totality of this body’ that prevents it from counting as a that Aristotle might have to accept as a definition. (The presence of a proper name would be similarly disqualificatory.)

25 There is an obvious connection between matter and thisness for Aristotle. The unknowability (cf. 1036a8) and indefiniteness (cf. 1037a27) of matter, and its banishment from proper definitions (cf. 1035b33, 1036b5-6) that we find in Z.10 and 11 may thus be due more to its purely indexical role than to anything else. More work needs to be done investigating this connection in Aristotle's metaphysics.

26 Well documented by Hartman, 59-60.

27 Anscombe, 94

28 Furth, 643

29 Furth, 644

30 Code, cited in n. 4 above

31 Those who believe that Aristotle had a notion of individual forms would be likely to invoke them at this point in an attempt to provide Aristotle with a satisfactory principle of diachronic individuation. (For an interesting exception, cf. Hartman, Ch. 2, passim, esp. p. 84.) I think it unlikely that Aristotle countenanced such entities; but the topic is too large to be considered within the confines of the present paper.

32 Furth colorfully describes this as the “migration resistance” condition. Cf. Topics 125b37-9 and 145a3-12 for the evidence that it is to be found in Aristotle.

33 It may be felt that I have cheated in allowing the second statue to be of a different person and by a different sculptor. The objection would be that the relevant species term is not ‘statue’ but ‘statue-of-Socrates-by-Praxiteles’ (or whomever). In that case my example would fail to satisfy the requirement of cospecificity that is built into the principle we are considering. Although I have my doubts about the objection, I think that we can grant it and still make the case. Let us suppose the same artist to be depicting the same subject in the postwar statue, but suppose that the first statue portrayed Socrates as a leering lecher, while the second gives him the dreamy-eyed look of a noble visionary. This is surely not the same statue as the original, although it is materially continuous and cospecific (in the stricter way that the objection requires) with the original. We may even suppose the sculptor to have duplicated the style and appearance of the original exactly and still have reasonable doubts about identifying the post-war statue with the original.

In any event, it is important to note that the case of artifacts is not offered as an objection to Code's analysis of continuing to be identical in terms of continuing to have the same matter, for the post-war statue does not, when it comes into existence, continue to have the same matter that some other statue also continues to have. Rather, the counterexample's only force would be against the idea of formulating a general principle of identity and diversity for temporally disparate individuals in terms of continuity of matter. (I owe notice of this point to Mohan Matthen.)

34 We have left open the question whether sameness of matter is a sufficient condition of diachronic identity for cospecific biological substances. The question is probably best ignored, since the condition will seldom be satisfied, given the regularity of the metabolic interchange that obtains between a plant or animal and its environment.

35 Although Furth does not actually formulate a principle of continuity of form, there are suggestions in his account (see esp. p. 642) that continuity of form is what he has in mind. For a more pessimistic assessment of Aristotle's treatment of diachronic identity, d. Hartman, 84. Hartman sees Aristotle as needing the notion of continuity of form, but making no explicit provision for it.

36 I discussed an earlier draft of this paper with members of the philosophy department at the University of British Columbia; I have benefited, too, from the helpful comments of an anonymous referee for the Canadian Journal of Philosophy.