384-322 b.c.. Greek philosopher. Born at Stagira, he went to Plato's school at Athens (367-347). After the death of Plato he lived in the Troad and on Lesbos, eventually becoming tutor to the son (the future [[Alexander the Great]]) of Philip II of Macedon. In 335 he returned to Athens to open a new school called the Lyceum. When Alexander died in 323, the school was in danger from the anti-Macedonian forces, so Aristotle took refuge on Euboea.