Lyceum, Athenian school founded by Aristotle in 335 bc in a grove sacred to Apollo Lyceius. Owing to his habit of walking about the grove while lecturing his students, the school and its students acquired the label of Peripatetics (Greek peri, “around,” and patein, “to walk”). The peripatos was the covered walkway of the Lyceum. Most of Aristotle’s extant writings comprise notes for lectures delivered at the school as edited by his successors.