Chapter 52

One should know that action and passion, or the active and passive potencies, come under quality, but that which acts and which is acted upon is some substance acting in a certain way. To act, then, is to have within oneself a cause of action, whereas to be acted upon is to have in oneself and in another the cause of being acted upon, as with the creator and the creature. Thus, the creator has in himself the cause of creation, whereas on the other hand, the creature has in the creator the principle of creation and in its own self the suitability of being acted upon. By creator we here mean the artisan, such, for example, as the carpenter. And by creature we mean the matter subjected to the artisan, such, for example, as wood, for this last is subjected to the carpenter.

Of the things which come under action and passion some are said simply to make and to be made, as in the case of the practical arts, such as wood-working, metal-working, and the like. With these the thing made endures even after the maker has ceased making. Thus, when the builder has finished building, that which has been built by him endures. Other things one is said to do, in which case that which is done does not last after the doer has ceased doing. Thus, when the flute-player has stopped playing, the flute-playing does not keep on, but stops entirely. In the case of other things one is said to consider, as in the practice of astronomy and geometry, and in thinking, and the like. Then, again, there are those other kinds which are observed in such inanimate beings as fire, stone, wood, and so forth. The first of all these concern rational beings, whereas the very last kind concerns the inanimate and irrational beings. For the inanimate being does not act as the animate beings do, but as a body approaching a body.

This category has two properties. The first is that it admits of contrariety, for to heat is the contrary of to cool. The second is that it admits of more and less, for it is possible to heat more and to cool less; similarly, with being heated and being cooled.

Activity and passivity, then, are observed in all the categories: in substance, begetting and being begotten; in quantity, counting and being counted; in relation, doubling and being doubled; in quality, whitening and being whit