  How great a problem this will be depends in part upon how entrenched Aristotle’s commitment to the mind’s being nothing in actuality before thinking turns out to be. It equally turns on how adaptable Aristotle’s hylomorphic account of change proves to be. On this latter point, Aristotle notes that according to his account, there are various different types of change and alteration, illustrated by the difference between a brown fence’s being painted white and a builder’s taking up his tools and beginning to build. In the first case, there is a destruction and a loss, of the fence’s original color; in the second case, nothing is destroyed, but rather that which is already dispositionally F becomes occurrently F by engaging in some F-ish activity. A builder is as such already able to build. When he begins building he becomes fully and actually a builder for the duration of his working. In this way, he loses nothing, but instead realizes an already established potential.