LYCÆUM, Λύκειον, in antiquity, the name of a celebrated school or academy at Athens, where Aristotle explained his philosophy. The place was composed of porticoes and trees planted in the quincunx form, where the philosophers disputed walking. Hence philosophy of the Lycæum is used to signify the philosophy of Aristotle, or the Peripatetic philosophy. Suidas observes, that the Lycæum took its name from its having been originally a temple of Apollo Lycæus; or rather a portico or gallery built by Lycæus son of Apollo; but others mention it to have been built by Pisistratus or Pericles.