Definition for Categories
From Biology Forums Dictionary
The rules used to hold thoughts together in a single consciousness. The word is close in meaning to the verb “to predicate,” and, for Aristotle, who first propounded a list of categories, it is precisely what can be predicated of substance that he details. Of primary importance for Aristotle (aside from substance itself) are quantity, quality, and relation, while Kant lists fully twelve different categories (although his scheme is often considered unconvincing).