at a potential is “a potentiality to do something, to do it at some time, and to do it in some way (and however many other conditions must be present in the definition)”. A potentiality is said to be realized when the change described takes place. A non-rational potential is realized when its conditions are met and there is no external barrier. A rational potentiality requires an element of “desire or decision” before it is necessarily realized. Clearly, a rational potentiality cannot possibly be realized in both of its contrary ways at once.Having finished with his discussion of potentiality, Aristotle now moves on to look at actuality. Since actuality is the realization of potentiality, there will be two types of actuality correspondent to the two types of potentiality previously mentioned. Aristotle says that “in some cases the actuality is that of motion in relation to potentiality, and in other cases it is the actuality of substance in relation to matter”. He describes actuality in relation to potentiality with a series of analogies. Some of these analogies seem to be illustrative of actuality as motion. Finally, Aristotle addresses the question of how we assign potentialities to things. He says that in the case of rational potentiality, we say that A is potentially B if A realizes B whenever it wishes to and nothing external prevents it. In the case of passive (non-rational) potentiality, we say that A is potentially B if nothing internal prevents it from doing so. For example, wood is potentially a fire. This is a case of passive potentiality. In the case where potentiality is internal to the thing we say that A is potentially B if nothing external prevents it from realizing B. For example, a seed in soil is potentially a tree. Aristotle doesn’t mention active non-rational potentiality, but it is probably the same. V.Unmoved MoverIn general, Aristotle does not seem to think th...
