Aristotle (Gr. Aristotle 100469 perhaps the greatest ancient philosopher, founder, of the school of Peripatetics, born in Stagira, a. Greek colony of Macedonia, near the mouth of the Strymon, in 384 B. C., died at Chalcis, on the island of Eubœa, in 322. From his birthplace | he was called "the Stagirite." He studied for a short time at Atarneus in. Asia Minor, and at 17 years of age went to pursue his studies in Athens, where he resided for 20 years. He was a pupil of Plato, whom he sincerely admired, though opposed to him in philosophy. Plato was accustomed to call him, on account of his enthusiasm for knowledge and his restless industry, the "intellect of his school." About 343 B. 0. Philip of Macedon made him the teacher of his son Alexander, at that time 13 years old. His influence on Alexander and Philip was for many years very great and salutary, and Philip rebuilt at his request the city of Stagira, which had been destroyed, and erected there, in a pleasant grove, a school called Nymphaeum, where Aristotle was to teach. Alexander after the conquest of the Persian kingdom presented him with 800 talents, or nearly a million of dollars.

He also sent to him whatever he discovered on his marches that was unknown in Greece, such as plants and animals for scientific examination, and is said to have been accompanied by him in several of his expeditions. Aristotle returned to Athens in 835, or, according to Am-monius, in 331, bringing with him his scientific collections, and established a new school of philosophy in the Lyceum, a gymnasium near the city. In the forenoon he instructed his intimate pupils in a philosophical way, which lectures were called esoteric; and in the evening he taught a large popular circle about plainer matters, in what were called exoteric or public lectures. His philosophical school is called the Peripatetic, because he taught while walking up and downAristotle 100470 or from the shady walksAristotle 100471 ) around the Lyceum in which he delivered his lectures, and which in the time of Plutarch were still pointed out to the traveller. His friendly relations with Alexander were at length interrupted, perhaps on account of admonitions which he sent to that conqueror when, in his later years, he precipitated himself into a dissolute life. Yet the Athenians suspected him of partisanship for Macedonia, accused him of impiety, and forced him to flee to Chalcis, where he died. - Only a part of his numerous writings on almost every branch of science and art were then published; of the remainder many were lost, and many published only in the first centuries of the Christian era. The most important of them bear the following titles: " Organon " or "Logic," "Rhetoric," "Poetics," "Ethics," " Politics," " History of Animals," " Physics," "Metaphysics," "Psychology," and "Meteorology." His writings on mathematics, economy, and history are lost, as well as his letters, and a work called Politiai, 'which contained 158 ancient state constitutions and legislations.

Many books bearing his name are spurious, and it is only in the present century that the spurious begin to he sifted from the genuine, His style is difficult to understand, not only because of the intricacy of the subjects, but also on account of the technical terms entirely his .own. No other philosopher has exerted so large an influence on so many centuries, and on the ideas of so many nations, as Aristotle. His merits as a metaphysical thinker may perhaps be variously estimated, but his performances in natural science, which he first created, and his method of philosophy, constitute his greatness. He was the first careful observer, dissector, and describer of animals. He first divided the animal kingdom into classes; described a great many animals before unknown to the scientific world; came near discovering the circulation of the blood; discriminated between the several faculties, the nourishing, feeling, concupiscent, moving, and reasoning powers of animal organism, and attempted to explain the origin of these powers within the body; and built his moral and political philosophy on the peculiarities of human organization. His philosophical method consists in the principle that all our thinking must be founded on the observation of facts.

Logic is the fundamental science, and the principles which he laid down for it have never been superseded. It is acknowledged by Kant and Hegel, the two most profound thinkers of Germany, that from the time of Aristotle to their own age logic had made no progress. He invented the categories, or fundamental forms of thought, universal expressions for the ever-changing relations of things, and limited their number to ten; and he devised the so-called " syllogistics," or science of forming correct conclusions. He likewise became the father of modern psychology, showing how the mind creates its speculative methods and general notions; and that though we cannot prove their correspondence with the reality, because there is no direct proof for things which transcend our senses and observation, yet we are always compelled to recur to these general notions and take them for indispensable forms of thinking, if we will think at all. Every science must, according to Aris-totle, have a fundamental principle, which need not and cannot be logically proved, because it is in itself certain, and accepted as manifest truth.

Aristotle first discriminated between the substance of things and their accidental peculiarities, and created the philosophical notions of "matter" and of "form." He also established the philosophical notions of" space " and "time," and showed their connection with matter, while he first furnished the world with what is commonly called the cosmological argument for the existence of God. He states it thus: Although every single movement and existence in the world has a finite cause, and every such finite cause another finite cause back of it, yet back of this infinite series of finite causes there must be an infinite immaterial being, a first something, unmoved, all-moving, pure energy, absolute reason, God. In psychology and anthropology, Aristotle is the author of the theory of different powers of the soul, of distinct feeling, willing, reasoning, and moving powers or faculties. The reasoning power is regarded by Aristotle not as a product of the body, but as bestowed on it from outside, and as perfect only after its separation from the body by death.

Proceeding from the principle that whatever is to be the goal and highest good of humanity must not depend on casualties and ever-changing minor circumstances, but must be certain in itself, and impart to every other good its value, he maintains that the eudaimonia, or highest possible pleasure which is conceivable for man, is derived only from the perfect satisfaction of those faculties which distinguish him from the beasts, that is, of the reasoning powers. - Of his earliest pupils and followers, none but Theophrastus, and he not strictly a philosopher is worth mentioning. The age after Aristotle's death was not favorable to purely speculative philosophy. For three centuries Stoicism and Epicureanism took the place of his philosophy in the favor of the educated world; and these were succeeded by Neo-Platonism. Later the philosophy of Aristotle was rendered obnoxious to the fathers of the church by the pagan tendencies of its expounders at Alexandria, but a few, like Boethius, ventured to defend his views. Up to the 11th century Aristotle was almost unknown to the Christian world, but he was a favorite with the Arabians of the 8th, 9th, 10th, and 11th centuries.

Through the Arabians, the scholastic writers of the 11th century made acquaintance with his " Physics" and "Metaphysics," though by means of very imperfect translations; his "Logic" they had, though not extensively, known before. From that time Aristotle, though sometimes disparaged as a heretic, remained for four centuries the authority of the Christian world in all matters not strictly pertaining to dogmas. In the 11th century the dispute between the nominalists and realists began to divide theologians; the realists asserting with Plato that our general notions, called universalia, are the substance of things, that our ideas answer not only to the reality of objects, but contain their soul and life; the nominalists, in the name of Aristotle, maintaining that these general notions are mere abstractions, inventions of the brain, not expressing the real substance of things. From the exposition that we have given, it appears that this pretended Aristote-lianism was a misunderstanding of Aristotle's philosophy, which, though it admits on the one hand that our general notions cannot be demonstrated to express the full substance of things, yet at the same time asserts that they are indispensable for every purpose of thinking.

After the restoration of classical literature in the 15th century, his writings were extensively published, and his philosophy began to be better understood; and it has been further developed by Bacon, Descartes, Spinoza, and Kant. Fichte, Schelling, and Hegel opposed it, though the latter adopted many of its ideas. It is, however, not so much by his philosophical system that Aristotle has wielded his enormous influence, especially as this is only now beginning to be fully understood and justly appreciated, as by his logical inventions, and his method of philosophy in general. - The best works on the contents, spirit, and bearings of the writings of Aristotle are Stahr's Aristote-lia (2 vols., Halle, 1830); Franz Biese's Philosophic des Aristoteles (2 vols., Berlin, 1835-'42); and "Aristotle," a posthumous work, by George Grote (London, 1872). The best complete edition of Aristotle is that of the academy of sciences at Berlin, by Immanuel Bekker (4 vols., Berlin, 1831-'6), with Latin translations and extracts from the old commentaries.