 According to the grammatical approach, which traces to Trendelenburg (1846) and has most recently been defended by Michael Baumer (1993), Aristotle generated his list by paying attention to the structures inherent in language. On the assumption that the metaphysical structure of the world mirrors the structures in language, we should be able to find the basic metaphysical structures by examining our language. This approach is quite involved but for our purposes can be illustrated with a few examples. The distinction between substance and the rest of the categories, for instance, is built into the subject-predicate structure of our language. Consider, for instance, the two sentences: (1) Socrates is a human; and (2) Socrates is white. First, we see that each sentence has a subject, namely ‘Socrates’. Corresponding to that subject, one might think, is an entity of some kind, namely a primary substance. Moreover, the first sentence contains what might be called an individuating predicate — it is a predicate of the form, a such and such, rather than of the form, such and such. So, one might think, there are predicates that attribute to primary substances properties the having of which suffices for that substance to be an individual of some kind. On the other hand, the second sentence contains a non-individuating predicate. So by examining the details of the predicates in our language, we have some grounds for distinguishing between the category of substance and the accidental categories.