  Fundamental to Aquinas' derivation of the categories is an isomorphism between language and reality. Only because language parallels reality in some way can Aquinas derive the ten categories of extra-mental things from the ten different kinds of predication he accepts; we know that there are ten different kinds of things based on the different ways something is “said of” or “predicated of” a subject. As John Wippel puts it, the “diverse modes of predication correspond to and reflect diverse ways in which being itself is realized, or what [Thomas] calls diverse modes of being (modi essendi). Moreover, this diversity in the order of predication follows from and depends upon diversity in the order of being” (Wippel 1987, 17).