After Alexander mounted the throne and undertook his Eastern conquests, Aristotle re turned to Athens in his fiftieth year, to carry out a plan, no doubt long cherished, of opening a school of his own. This he established in the Lyceum, in a building called "The Walk" (7rephraroc), where lie lectured. AN'e hear from fill untrustworthy tradition that lie gave two kinds of instruction: in the morning to a nar row circle of advanced pupils (his esoteric doctrine), and in the evening, more popular lectures (exoteric teaching) to a larger body of listeners. The name Peripatetic, applied to the school and its philosophy, ca.nnot he traced earlier than n.c. 200. Of the equipment of the school, in hooks and material, we know nothing. Aristotle continued to teach for twelve years, until Alexander's death, in B.C. 323, made his po sition in Athens dangerous. He was charged with impiety, but fled to Chalcis, as lie said, to save the Athenians from a second sin against philosophy. Here he died, in B.C. 322. in his sixty-third year. Theophrastus and Eudemus were his immediate successors in the leadership of the school.
Aristotle left behind him an enormous num ber of writings. Diogenes Laertius, of uncertain date, gives us a list of 46 works. This probably represents the works bearing Aristotle's name in the Alexandrian Library. A list dating from the time of Cicero makes the total much larger. An ancient tradition says that at the death of Theophrastus, his library, including of course the works of Aristotle, was left to a certain Neleus of Scepsis. His descendants buried the books to save them from the rapacity of the Attalids, who were eager to enrich the Perga mene Library by every possible means. About B.C. the buried collection, naturally much injured by damp and worms, was discovered by Apellicon of Teos. a learned bibliophile, who brought it to Athens. When Sulla captured the City, B.C. 86, he took the books to Rome. where their value was recognized by the grammarian Tyrannion, who had a catalogue prepared by the Peripatetic Andronicus—the longer lig men tioned above—and about 46 B.C. pablished the works thus recovered. Our present recension undoubtedly goes back to this edition, although it is lucre immediately related to a recension prepared toward the end of antiquity which embraced a number of spurious writings. The later Prripatetics divided the complete works of their master into two classes: exoteric dia logues intended for the public, and acroamatic for the small circle of pupils. To these may be added as a third class certain writings not intended for publication, the hyponmematic works consisting of memoranda and collections on various topics. The exoteric dialogues were well known and much admired in antiquity, but only bare fragments have come down to us. These dialogues did not possess the dra
matic character of Plato's works; in place of question and answer, they had long discourses, such as we find in the philosophical writings of Cicero, who chose Aristotle as his model. Among the titles known to 11A are On the Immortality of the Soul, On Philosophy, On the Good, On Justice, etc. Certain titles, e.g. Menexenus, Gryll-us, Nerinthus, The Sophist, etc., remind us of Plato's dialogues. Aristotle carefully prepared these for publication, and must have exhibited in them that perfection of style which caused Cicero to speak of the philosopher's language as a golden stream. The extant works show but little of this quality. These were never com pletely prepared, and in many cases probably never intended for publication by Aristotle, but were edited by Theophrastus, Eudemus, and the philosopher's son. Nicomachns. Many have the character of lecture notes, possibly those taken by pupils, and most have suffered from interpola tions. A considerable number of the works to which his name is now attached are spurious. The extant writings may be classed according to their contents under Logic, Metaphysics, Natural Science, Ethics and Politics, Rhetoric and Poetics.
The works on Logic were called by the later Peripatetics the Organon, "The Instrument," as they deal with the method of investigation. They include the Categories, on the ten classes of predicates—substance, quantity, quality, etc.; On Interpretation, dealing with the proposition and its parts; Analytic(' Priora, in two hooks on the syllogism; Analytic(' Posteriors in two books on the theory of knowledge and the scientific method; Topica in eight books, on dialectics and reasoning from probabilities; and Sophisms on the fallacies of the Sophists and their solution. Aristotle's claim that he was the first to work out a method of reasoning was correct, and formal logic has made little advance since his day; it has only added to his categorical syllo gism the hypothetical and disjunctive forms, and has supplemented his three figures by a fourth.
The Metaphysics in thirteen books bears the name given it by later students, because it fol lowed the works on physics in the ancient edi tions of Aristotle. The philosopher himself called it "First Philosophy" (rpdrrn cp/Xoa-oofa). It is in an unsatisfactory condition, consisting of one finished treatise and a number of shorter sketches hardly connected or fully worked out. It begins with a criticism of previous philosoph ical systems—the earliest history of philosophy —and then, after stating the philosophical ques tions preliminary to the examination, discusses the doctrine and the ultimate grounds of Being.