METAPHYSICS form, but not parts of the matter Parts of the form are to be identiWed by the method of deWnition by division, into genus and species, that we met in Plato’s later dialogues We can now see why it is misguided to ask whether Socrates’ body is part of his quiddity Body and soul are parts of Socrates (parts of a rather special kind, as will be explained in the next chapter) Being rational and being animal are parts of the quiddity of Socrates, and being animal includes having a body (an organic body of a particular kind) But having a body is not at all the same as a body To ask whether Socrates’ body is part of his quiddity is to fall into the confusion of concrete and abstract of which we were earlier tempted to accuse Aristotle himself On the other hand, we must say something similar about soul The soul cannot simply be identiWed with the quiddity, as Aristotle sometimes incautiously suggests: to be human is to have a soul of an appropriate kind incarnate in an organic body We have done our best to make sense of the doctrine of substance in the Metaphysics The topic was introduced by Aristotle as a method of answering the fundamental question, What is being? It is now time to address that question frontally Being and Existence It is clear that Aristotle uses the expression to on in the same manner as Parmenides: Being is whatever is anything whatever Whenever Aristotle explains its meaning he does so by explaining the sense of the Greek verb ‘to be’ (e.g D 1017a6 V.; F 1028a19 V.) Being contains whatever items can be the subjects of true sentences containing the word ‘is’, whether or not the ‘is’ is followed by a predicate Both ‘Socrates is’ and ‘Socrates is wise’ tell us something about Being Predicates in all the categories, Aristotle tells us, signify being, because any verb can be replaced by a predicate that will contain the copula ‘is’: ‘Socrates runs’, for instance, can be replaced by ‘Socrates is a runner’ Every being in any category other than substance is a property or modiWcation of substance That is why the study of substance is the way to understand the nature of Being With Aristotle, as with Parmenides, it is a mistake to equate being with existence In the dictionary entry for ‘being’ in the philosophical lexicon 223