Abstract

BOOK Z OF THE METAPHYSICS is generally held to contain Aristotle's most comprehensive investigation of what we have come to call essence. One might reasonably be led back to that text, then, by the recent renewal of interest in essentialism, more particularly, by the debate about the merits of "Aristotelian essentialism." This is the label Quine employed in objecting to the doctrine--which he thought quantified modal logic was compelled to accept--that objects have, independent of our ways of specifying them, necessary properties distinguishable from contingent ones; it is the label commonly applied to a thesis about general essence, referring to those properties which make an individual a member of a certain kind without individuating one such member from another. Whether a defense of "Aristotelian essentialism" is to be found in book Z of the Metaphysics, however, is far from obvious. The contemporary interest in defending essentialism, for one thing, is associated with a variety of related problems, including those of identity over time and across possible worlds, the status of natural kinds and of the laws of nature; and while Aristotle's discussion may not be irrelevant to these issues, they are not what is explicitly thematized in Book Z. The chief and primary and practically only concern "for us," Aristotle announces, is to theorize about being in its primary sense, what it is. It is not only in this concern that Aristotle may sound rather remote to contemporary ears, but, perhaps most conspicuously, in the odd formula he coins for what is traditionally translated "essence," namely, "the what-it-was-to-be." We are especially led to wonder just what notion Aristotle has in mind, and what role it plays, by the puzzling question he pursues through the central chapters of book Z: is each thing the same as its what-it-was-to-be?