  None of this, however, is very clear. Indeed, Aristotle never actually says that categories are words, concepts, or realities; he only speaks of them as categories, that is, predicates. But ‘predicate’ can be used to mean realities, concepts, or linguistic terms. Aristotle does speak of categories as if they were realities or linguistic terms, and one can further infer that he could have spoken of them as if they were concepts. But this does not definitely clarify what he thinks about them. Indeed, on the basis of what he says we cannot determine for sure that he even raises the question of the ultimate ontological status of categories.  The situation is further obscured because Aristotle never identifies the discipline where categories are supposed to be studied and he treats them in both logical (Categories, Topics) and metaphysical (Metaphysics) contexts.