Plato [plA´tO] , 427?–347 B.C., Greek philosopher. Plato's teachings have been among the most influential in the history of Western civilization.
After pursuing the liberal studies of his day, he became in 407 B.C. a pupil and friend of Socrates. From about 388 B.C. he lived for a time at the court of Dionysius the Elder, tyrant of Syracuse. On his return to Athens, Plato founded a school, the Academy, where he taught mathematics and philosophy until his death. His teaching was interrupted by two more visits to Syracuse (367 and 361 B.C.), which he made in the vain hope of seeing his political ideals realized in Sicily.
Plato was a superb writer, and his works are part of the world's great literature. His extant work is in the form of dialogues and epistles. Some of the dialogues and many of the epistles attributed to him are known to be spurious, while others are doubtful. In the various dialogues he touched upon almost every problem that has occupied subsequent philosophers. The dialogues are divided into three groups according to the probable order of composition.
The earliest group of dialogues, called Socratic, include chiefly the Apology, which presents the defense of Socrates; the Meno, which asks whether virtue can be taught; and the Gorgias, which concerns the absolute nature of right and wrong. These early dialogues present Socrates in conversations that illustrate his main ideas : the unity of virtue and knowledge and of virtue and happiness. Each dialogue treats a parout necessarily resolving the issues raised.
See translation of the dialogues by B. Jowett, ed. by D. J. Allan and H. E. Daley (4 vol., 4th ed., rev. 1953); A. E. Taylor, Plato: The Man and His Work (1927); R. Bambrough, ed., New Essays on Plato and Aristotle (1965); G. Vlastos, Platonic Studies (1973); G. F. Else, Plato and Aristotle on Poetry (1987); Jacob A. Kline, A Commentary on Plato's Meno (1989); C. Hampton, Pleasure, Knowledge, and Being: An Analysis of Plato's Philebus (1990).
Academy, school founded by Plato near Athens c.387 B.C. It took its name from the garden (named for the hero Academus) in which it was located. Plato's followers met there for nine centuries until, along with other pagan schools, it was closed by Emperor Justinian in A.D. 529. The Academy has come to mean the entire school of Platonic philosophy, covering the period from Plato through Neoplatonism under Proclus. During this period Platonic philosophy was modified in various ways. These have been frequently divided into three phases: the Old Academy (until c.250 B.C.) of Plato, Speusippus, and Xenocrates; the Middle Academy (until c.150 B.C.) of Arcesilaus and Carneades, who introduced and maintained skepticism as being more faithful to Plato and Socrates; and the New Academy (c.110 B.C.) of Philo of Larissa, who, with subsequent leaders, returned to the dogmatism of the Old Academy.