Marsilio Ficino’s Platonic Theology, Volume I

11Thus water cools through coldness, and fire heats through heat rather than through bulk. Fire burns not because it is very large, but because it is very hot. If all its heat is concentrated, as it were, into a point, it will be supremely powerful to burn because of that maximal union. Thus action arises by the agency of quality, especially when quality is compressed into a narrow compass.

12It follows that natural causes produce effects more like their causes in quality than equal to them in quantity. Even if the effects sometimes come to equal their causes, they must first have appeared very like them. This suggests that action is carried out through qualities, since in and through qualities effects necessarily reproduce their causes. Thus nearly all children, as soon as they are born, resemble their parents in constitution and shape; equality in size is rarer and comes later.

13But who has failed to see this? If you approach a large body, you do not thereby become large; if you approach a hot body, however, you certainly grow warm. Nor do you perceive quantity with any sense unless quality has first moved the sense. Who could judge how large a wall is unless color and light conveyed it all the way to the eye in that very magnitude? Moreover, because of distance our judgment of quantity is lost more fully and sooner than our judgment of light and color—as though the efficacy of motion lay in quality.

14This is plainly confirmed here: every object always moves appetite in respect of its goodness—which is a quality—not in respect of magnitude or number. Otherwise we would always choose things that are larger or more numerous. Yet among things we regard as bad, we choose those that are smaller or fewer.