Much of the debate about identity in recent decades has been about personal identity, and specifically about personal identity over time, but identity generally, and the identity of things of other kinds, have also attracted attention. Various interrelated problems have been at the centre of discussion, but it is fair to say that recent work has focussed particularly on the following areas: the notion of a criterion of identity; the correct analysis of identity over time, and, in particular, the disagreement (...) between advocates of perdurance and advocates of endurance as analyses of identity over time; the notion of identity across possible worlds and the question of its relevance to the correct analysis of de re modal discourse; the notion of contingent identity; the question of whether the identity relation is, or is similar to, the composition relation; and the notion of vague identity. A radical position, advocated by Peter Geach, is that these debates, as usually conducted, are void for lack of a subject matter: the notion of absolute identity they presuppose has no application; there is only relative identity. Another increasingly popular view is the one advocated by Lewis: although the debates make sense they cannot genuinely be debates about identity, since there are no philosophical problems about identity. Identity is an utterly unproblematic notion. What there are, are genuine problems which can be stated using the language of identity. But since these can be restated without the language of identity they are not problems about identity. (For example, it is a puzzle, an aspect of the so-called “problem of personal identity”, whether the same person can have different bodies at different times. But this is just the puzzle whether a person can have different bodies at different times. So since it can be stated without the language of personal “identity”, it is not a problem about identity, but about personhood.) This article provides an overview of the topics indicated above, some assessment of the debates and suggestions for further reading. (shrink)

Aristotle frequently describes essence as a “cause” or “explanation”, thus ascribing to essence some sort of causal or explanatory role. This explanatory role is often explicated by scholars in terms of essence “making the thing be what it is” or “making it the very thing that it is”. I argue that this is problematic, at least on the assumption that “making” expresses an explanatory relation, since it violates certain formal features of explanation. I then consider whether Aristotle is vulnerable to (...) this problem by examining the explanatory role of essence in Posterior Analytics and Metaphysics Z 17. (shrink)

I formulate an apparent inconsistency between some claims Aristotle makes in his Metaphysics about the sameness and non-sameness relations which obtain between an object and its essence: while a object is not the same as its essence, an essence is thought as being the same as its essence. I discuss different ways in which one may propose to overcome this apparent inconsistency and show that they are problematic. My diagnosis of the problem is that all these putative solutions share the (...) assumption that Aristotle is operating exclusively with the notion of strict numerical identity between an object and its essence, or between definiendum and definiens. I introduce the notion of sameness in nature which holds between an object and its essence, understood as the metaphysical counterpart to the relation of 'being defined as': two items are the same in nature just in case the answer to the 'what is it?' or 'what is its nature/essence?' question is common to both. I argue that the notions of sameness in nature and 'being defined as' need not entail strict identity. Further, they are compatible with, indeed require, the idea that an essence is prior to its essence-bearer, or that a definiens is prior to the relevant definiendum. I conclude that the twin notions of sameness in nature and 'being defined as' successfully defuse the apparent inconsistency formulated at the outset. (shrink)

Michael J. Loux here presents a fresh reading of two of the most important books of the Metaphysics, Books Z and H, in which Aristotle presents his mature ...

When aristotle identifies form with substance he may have sufficiently refuted heraclitus' contention that we cannot step into the same river twice, But he is left with two problems: (1) how an object can have matter but be identical to its essence and different from its matter; and (2) there are some questions about the conditions for identity of a substance across time. (staff).

Virtually everyone will agree that according to Aristotle, for a particular substance to be is at least for it to be a thing of a certain kind. Every particular substance falls under a substance kind, where the essence of that particular substance at least includes the essence of its substance kind. For example, for a particular man to be is at least for him to be characterized by those predicates that make something a man. More generally, if A is said (...) of a particular A kath’ hauto, then the essence of that particular A will at least include the essence of the kind A. Let us call the first of these essences the essence of a particular A, and the second the essence of the kind A. The question now is whether Aristotle would maintain that the essence of a particular A includes the essence of the kind A for every kind A. In particular, would he maintain this when A is said of a particular subject kata sumbebêkos? For example, would he say that what it is for a particular pale man to be includes what it is to fall under the kind pale man? (shrink)

Frank A. Lewis presents a close study of book Zeta of Aristotle's Metaphysics, one of his most dense and controversial texts, commonly understood to contain his deepest thoughts on the definition of substance and related metaphysical issues. Lewis argues that Aristotle returns to the causal view of primary substance from his Posterior Analytics.

The Oxford Classical Texts, or Scriptorum Classicorum Bibliotheca Oxoniensis, are renowned for their reliability and presentation. The series consists of a text without commentary but with a brief apparatus criticus at the foot of each page. There are now over 100 volumes, representing the greater part of classical Greek and Latin literature.

Michail Peramatzis presents a new interpretation of Aristotle's view of the priority relations between fundamental and derivative parts of reality, following ...

Aristotle's claim in Metaphysics Z.6 that "each substance is the same as its essence" has long puzzled commentators. For it seems to conflict with two other Aristotelian theses: (1) primary substances are individuals (e.g., Socrates and Callias), and (2) essences are universals (e.g., Man and Horse). Three traditional solutions to this difficulty are considered and rejected. Instead, to make the Z.6 equation consistent with (1) and (2), I propose that it be interpreted to be making something other than a straightforward (...) identity claim. Callias is the same as his essence in the sense that to be identical to Callias is to be the same man as Callias (where Man is the essence of Callias). In general, x is identical to y if, and only if, x and y are the same E (where E specifies the "what it is to be" for x, i.e., the essence of x). So each of Socrates and Callias is the same as his essence, and Man is that essence, but Socrates and Callias are not identical, for they are not the same man. (shrink)