Aristotle

Aristotle (384–322 BCE) was born in Stagira, a Greek city in Chalcidice, into a family with deep ties to the Macedonian court: his father Nicomachus served as physician to king Amyntas III. Orphaned early, he traveled to Athens around age seventeen to study at Plato's Academy, where he remained for nearly two decades, first as student and then as teacher. After Plato's death in 347 BCE he left Athens for the court of Hermias of Atarneus in Asia Minor; with his colleague Theophrastus he conducted biological field research on Lesbos before being summoned by Philip II of Macedon to tutor the future Alexander the Great.

Aristotle's intellectual reach is unprecedented in antiquity. His extant works span formal logic (the syllogism and the categories), metaphysics (substance, form and matter, the unmoved mover), physics, biology and zoology, psychology, ethics, politics, rhetoric, and poetics. Methodologically he combined careful empirical observation — most visible in the zoological works — with logical analysis and dialectic, grounding abstract principles in observable phenomena. Where Plato pursued transcendent Forms, Aristotle insisted that form is immanent in particular things and that knowledge of nature begins with what is more familiar to us.

Returning to Athens in 335 BCE he founded the Lyceum (the Peripatetic school), named for its covered walkway. After Alexander's death in 323 BCE anti-Macedonian feeling forced his departure to Chalcis on Euboea, where he died the following year. Theophrastus succeeded him and inherited the library; the corpus passed through Hellenistic hands and was systematically edited by Andronicus of Rhodes in the first century BCE, the form in which it has reached us.

His influence shaped three medieval traditions. Islamic philosophy received him through al-Farabi, Ibn Sina (Avicenna), and Ibn Rushd (Averroes), whose commentaries themselves became canonical. Jewish thought engaged him centrally through Maimonides, whose Guide for the Perplexed sets out a rigorously Aristotelian framework for Jewish metaphysics. Latin Christianity absorbed him through twelfth- and thirteenth-century translations and the synthesis of Thomas Aquinas, whose Summa Theologiae fuses Aristotelian metaphysics with Christian doctrine. Modern logic, biology, ethics, and the philosophy of science all retain Aristotelian vocabulary and questions.