  In both kinds of alterations, Aristotle is happy to speak of an affected thing as receiving the form of the agent which affects it and of the change consisting in the affected thing’s “becoming like” the agent (De Anima ii 5, 418a3–6; ii 12, 424a17–21). So there is in both cases a hylomorphic model of alteration involving enforming, that is, a model according to which change is explained by the acquisition of a form by something capable of receiving it. Consequently, whatever is changed in a given way is necessarily such that it is capable of being changed in that way. This is not the mere triviality that whatever becomes actually F must already be possibly F. Instead, it is the recognition that specific forms of change require suitable capacities in the changing subjects, and that, consequently, analyses of specific forms of change will necessarily involve consideration of those capacities. No marshmallow can receive the form of an actual automobile; and only entities capable of perceiving can receive the perceptible forms of objects. This is Aristotle’s meaning when he claims: “the perceptive faculty is in potentiality such as the object of perception already is in actuality” and that when something is affected by an object of perception, “it is made like it and is such as that thing is” (De Anima ii 5, 418a3–6).