Chapter XVII.—Aristotle; Duality of Principles; His Categories; His Psychology; His Ethical Doctrines; Origin of the Epithet "Peripatetic."

Aristotle, who was a pupil of this (Plato), reduced philosophy into an art, and was distinguished rather for his proficiency in logical science, supposing as the elements of all things substance and accident; that there is one substance underlying all things, but nine accidents,—namely, quantity, quality, relation, where, when, possession, posture, action, passion; and that substance is of some such description as God, man, and each of the beings that can fall under a similar denomination. But in regard of accidents, quality is seen in, for instance, white, black; and quantity, for instance two cubits, three cubits; and relation, for instance father, son; and where, for instance at Athens, Megara; and when, for instance during the tenth Olympiad; and possession, for instance to have acquired; and action, for instance to write, and in general to evince any practical powers; and posture, for instance to lie down; and passion, for instance to be struck. He also supposes that some things have means, but that others are without means, as we have declared concerning Plato likewise. And in most points he is in agreement with Plato, except the opinion concerning soul. For Plato affirms it to be immortal, but Aristotle that it involves permanence; and after these things, that this also vanishes in the fifth body, ^[123] which he supposes, along with the other four (elements),—viz., fire, and earth, and water, and air,—to be a something more subtle (than these), of the nature of spirit. Plato therefore says, that the only really good things are those pertaining to the soul, and that they are sufficient for happiness; whereas Aristotle introduces a threefold classification of good things, and asserts that the wise man is not perfect, unless there are present to him both the good things of the body and those extrinsic to it. ^[124] The former are beauty, strength, vigour of the senses, soundness; while the things extrinsic (to the body) are wealth, nobility, glory, power, peace, friendship. ^[125] And the inner qualities of the soul he classifies, as it was the opinion of Plato, under prudence, temperance, justice, fortitude. This (philosopher) also affirms that evils arise according to an opposition of the things that are good, and that they exist beneath the quarter around the moon, but reach no farther beyond the moon; and that the soul of the entire world is immortal, and that the world itself is eternal, but that (the soul) in an individual, as we have before stated, vanishes (in the fifth body). This (speculator), then holding discussions in the Lyceum, drew up from time to time his system of philosophy; but Zeno (held his school) in the porch called Poecilé. And the followers of Zeno obtained their name from the place—that is, from Stoa—(i.e., a porch), being styled Stoics; whereas Aristotle's followers (were denominated) from their mode of employing themselves while teaching. For since they were accustomed walking about in the Lyceum to pursue their investigations, on this account they were called Peripatetics. These indeed, then, were the doctrines of Aristotle.