Aristotle was born in 384 B.C. at Stagira, a small coastal town in northern Greece. His father, Nicomachus, was a physician to the Macedonian ruler Amyntas II. His mother was Phaestis, a descendant of a family from Chalcis who had moved their home to Stagira. Aristotle no doubt inherited his interest in the study of nature from his father's family, which had traditionally practiced medicine. It is quite probable that, under the influence of his father, Aristotle himself studied medicine. He may even have practiced dissection. Both his parents died while he was young, and Proxenus, one of his relatives, became his guardian.

Two ancient biographical sources, Diogenes Laertius and Dionysius of Halicarnassus, agree about the four major chapters of Aristotle's life: his childhood in Macedonia, his education at Plato's Academy, his travels in Asia Minor and Macedonia, and his return to Athens as head of his own...