Note (return) — Chapter X

Plato commences this inquiry by first defining his understanding of the word δύναµις--power or faculty. "We will say faculties (δυνάµεις) are a certain kind of real existences by which we can do whatever we are able (e.g., to know), as there are powers by which every thing does what it does: the eye has a power of seeing; the ear has a power of hearing. But these powers (of which I now speak) have no color or figure to which I can so refer that I can distinguish one power from another. In order to make such distinction, I must look at the power itself, and see what it is, and what it does. In that way I discern the power of each thing, and that is the same power which produces the same effect, and that is a different power which produces a different effect." 522 That which is employed about, and accomplishes one and the same purpose, this Plato calls a faculty.