Lyceum, (1) an extensive ancient sanctuary of Apollo just east of Athens, the site of public athletic facilities where Aristotle taught during the last decade of his life; (2) a center for philosophy and systematic research in science and history organized there by Aristotle and his associates; it began as an informal group and lacked any legal status until Theophrastus, Aristotle’s colleague and principal heir, acquired land and buildings there c.315 B.C. By a principle of metonymy common in philosophy (cf. ‘Academy’, ‘Oxford’, ‘Vienna’), the name ‘Lyceum’ came to refer collectively to members of the school and their methods and ideas, although the school remained relatively non-doctrinaire. Another ancient label for adherents of the school and their ideas, apparently derived from Aristotle’s habit of lecturing in a portico (peripatos) at the Lyceum, is ‘Peripatetic’. The school had its heyday in its first decades, when members included Eudemus, author of lost histories of mathematics; Aristoxenus, a prolific writer, principally on music (large parts of two treatises survive); Dicaearchus, a polymath who ranged from ethics and politics to psychology and geography; Meno, who compiled a history of medicine; and Demetrius of Phaleron, a dashing intellect who wrote extensively and ruled Athens on behalf of foreign dynasts from 317 to 307. Under Theophrastus and his successor Strato, the school produced original work, especially in natural science. But by the midthird century B.C., the Lyceum had lost its initial vigor. To judge from meager evidence, it offered sound education but few new ideas; some members enjoyed political influence, but for nearly two centuries, rigorous theorizing was displaced by intellectual history and popular moralizing. In the first century B.C., the school enjoyed a modest renaissance when Andronicus oversaw the first methodical edition of Aristotle’s works and began the exegetical tradition that culminated in the monumental commentaries of Alexander of Aphrodisias (fl. A.D. 200). See also ACADEMY , ANDRONICUS OF RHODES , ARISTOTLE , COMMENTARIES ON ARISTOTLE , STRATO OF LAMPSACU. S.A.W.