Whatever may he the explanation, he went in his 37th year, after a stay of nearly 20 years in Athens, to the Mysian town of Atarneus, in Asia Minor, opposite to the island of Lesbos. Here he lived with Hermeias, the chief of the town, a man of sin gular energy and ability, who had conquered his dominion for himself from the Per sians, at that time masters of nearly all Asia Minor. A. had taught him rhetoric at Athens, and he became in return the attached friend and admirer of his teacher. For three years the two lived together in the stronghold of Atarneus; but by treachery and false promises, Ittre Illioaianliontoivarr officer in The Persian 'service; got possession of the person of Hermeias, put him to death, and became master of all the places held by him. . A. accordingly fled, and took refuge in Mitylene, the chief city of the neigh boring island of Lesbos. He also took with him Pythias, the sister of Hermeias, and made her his wife. In a noble ode, he has commemorated the merits of his friend thus lost to him through the treachery of a Greek renegade. His wife, Pythias, died a few years afterwards in Macedonia, leaving him a daughter of the same name. his son, Xikomachus, to whom lie dedicated his chief work on ethics—called, in consequence, Nikomachean, Ethics—was born to him at a later period of his life by a concubine.
After two years' stay at Mitvlene, he was invited (in the year 342 B.0 age 42) by Philip to Macedonia, to educate hisson Alexander, then in his 14th year. What course of study Alexander was made to go through, we cannot state. He enjoyed the teaching of A. for at least three years, and contracted a strong attachment to his preceptor, which events afterwards converted into bitter enmity. The two parted finally when Alexander commenced his expedition into Asia (334 B.c.), and A. Caine from Macedonia to Athens, having recommended to the future conqueror, as a companiZm in his cam paigns, the philosopher Calisthenes, whom he educated along with Alexander. Now at the age of 50, he entered on time final epoch of his life; he opened a school called the " Lyceum," from its proximity to the temple of Apollo Lyceius. From his practice of walking up and down in the garden during his lectures arose the other name of his school and sect, the Peripatetic. It would appear to have been his habit to give a morn ing lecture to select pupils on the more abstruse subjects, and one in the evening of a more popular kind to a general audience. lie may now be supposed to have composed his principal writings; but, unfortunately, there is nothing known of the dates of any of them. This crowning period of his life lasted twelve years. After the death of Alexander, the anti-Macedonian party at Athens obtained an ascendency, and among other consequences, an accusation was prepared against A., the pretext being impiety.
With the fate of Socrates before his eyes, he chose a timely escape, and in the beginningof 322 B.C., took refuge at Chalcis in Eubcea, where, in the autumn of the same year, he died, aged O. Be had long been afflicted with indigestion, and ultimately sank under this malady.
The philosophy of A. differed from that of Plato on many points, especially in the fundamental doctrine termed the theory of ideas. The Platonic " ideas" or "forms" were conceived as real existences, imparting all that is common to the particular facts or realities, instead of being derived from them by an operation of the mind. Thus, the actual circles of nature derive their mathematical properties from the pre-existing "idea," or circle in the abstract; the actual men owe their sameness to the ideal man. A. was opposed to this doctrine throughout, although he always speaks of its author with respect, and sometimes with affection. The whole method of A. was in marked contrast to the Platonic handling of philosophical subjects: be was a most assiduous observer and collector of facts, from which he drew inductions with more or less accuracy. Plato, on the other hand, valued facts merely in criticising the views that he was bent upon demolishing, and not as a means of establishing sound theories.
The writings of A. may be said to have embraced the whole circle of the knowledge of his time. Many of them are lost; those that remain refer principally to the follow ing departments.
Astronomy, mechanics, physics, were treated of by him at some length; but here his failure was complete, if we look at his writings from the point of view now acquired. lie was the victim of capricious fancies, based upon doctrines common among his contemporaries, accepted by him as principles of reasoning, and conducting him to the most unsound conclusions. His theory of the rotation of the sphere, the necessary per fection of circular motion, of the impossibility of a vacuum, and the like, did more to confu than to explain the phenomena of nature. Nor can it be said that the time was not ripe for putting these subjects on a rational basis; for he was very shortly followed by a series of men, who both observed and reasoned soundly respecting them, and laid the foundation of their great subsequent progress—namely, Euclid, Apollonius, Archi medes, Eratosthen es, and Hi pparch us.
The thirteen hooks called metaphysics contain much profound thought, but are obscure and defectively arranged; indeed, neither the actual arrangement of the books nor the title which they bear, can be ascribed to A. himself. The subject to which they are devoted is ontology—time science of ens, quatenus ens—which he terms philosaphia prima, and sometimes theology. He distinguishes three branches of theoretical philos ophy. 1. Physics—the study of sensible material particular things, each of which differs from every other, and all of which have in themselves the principle of change or motion. 2. Mathematics—that of geometrical and numerical entities, known by general definitions, susceptible neither of change nor of movement, capable of being considered and reasoned upon apart from matter, but not capable of existing apart from matter. 3. The first or highest philosophy—which studies the essences of things eternal, unchangeable, and apart from all that change, movement, and differentiation which material embodiment involves.