Nicomachean Ethics

Medicinæ erga philosophiam consideratio.[philoso]phy holds among other arts and sciences, since he says that it is the art of arts and the science of sciences; for other arts and faculties seem to take their principles or their subjects from philosophy, and to be subject to it in some manner. For instance, medicine considers the human body in that respect by which it is subject to sickness or health; it likewise assumes that there are four elements and just as many primary qualities, as well as four humors and nine complexions; moreover, it takes principles of this kind: that contraries are the remedies for contraries, that ulcers which are of a round and circular shape are more slowly healed, and other things of the same kind—all of which it receives from philosophy itself and from the mathematical sciences. Just as grammar also receives sounds, quantities, and the measure of speech; likewise architecture itself, and the art of constructing machines, and other faculties take their principles or subjects from philosophy, as we have said, and they regard it as if it were a presiding authority, whether they exist outside of it or are parts of it. Deservedly, therefore, is it called by the Philosopher Aristotle the art of arts and the science of sciences. But if we wish to adapt this definition to first philosophy alone, it will not seem absurd to attribute this dignity to it in respect to the other sciences which receive their principles or subjects from it; and for this reason it is called wisdom, and the mistress of the remaining sciences, and the greatest science by the Philosopher in the book of the Posteriors. Therefore, the six definitions or descriptions brought forward seem to indicate sufficiently what philosophy itself is, and also to suggest in what subject it consists. Now, however, it seems we must proceed to its division, as we established from the beginning.

Philosophiæ diuisio.Philosophy, according to the common practice of almost everyone, is usually divided into two parts, one of which they call active and the other speculative; and although to one investigating more subtly such a division will perhaps not seem to be essential,