Nicomachean Ethics

Aristotle (384–322 BCE) was born in Stagira, a small city on the northern coast of Greece, the son of a royal physician. At seventeen he traveled to Athens and enrolled in Plato's Academy, where he studied for twenty years—first as a student, then as a teacher. He was Plato's most brilliant pupil, and also his most persistent critic. While Plato believed that true reality existed in abstract, eternal Forms, Aristotle insisted that knowledge had to be grounded in the observable world. He wanted to understand things as they actually are.

After Plato's death, Aristotle left Athens. He spent several years on the island of Lesbos doing the detailed biological fieldwork that produced some of the most comprehensive studies of animal life in the ancient world—dissecting, classifying, observing. He was as meticulous about a squid's anatomy as he was about the structure of a tragic plot or the nature of a friendship. Then, in 343 BCE, Philip II of Macedon invited him to tutor the king's thirteen-year-old son. That boy was Alexander, later called the Great. For three years Aristotle taught him Homer, rhetoric, medicine, and philosophy. What Alexander absorbed from those lessons—and what he ignored—shaped the course of Western history.

In 335 BCE, Aristotle returned to Athens and founded his own school: the Lyceum. He lectured while walking the colonnaded walkways, earning him and his followers the name Peripatetics—the walkers. His output was staggering. He wrote on logic, biology, physics, metaphysics, rhetoric, poetics, politics, psychology, and ethics. What survives today is thought to be his lecture notes and working drafts, not the polished dialogues he published in his lifetime—which means we are reading Aristotle at his most direct and technical, not his most literary.

He also made foundational contributions to logic that would remain essentially unchallenged until the nineteenth century. His syllogistic reasoning—the formal structure of deductive argument—shaped how Western thinkers reasoned for two thousand years.

In 323 BCE, Alexander died. Anti-Macedonian sentiment swept Athens, and Aristotle, too closely associated with the Macedonian court, faced charges of impiety—the same charge that had killed Socrates sixty years earlier. Unwilling to let Athens sin twice against philosophy, he fled to Chalcis, where he died the following year at sixty-two.

His influence on Western thought cannot be overstated. Medieval Christian theology was built on an Aristotelian framework: Thomas Aquinas spent his career reconciling Aristotle with Christianity. Islamic philosophers—Averroes and Avicenna above all—preserved and extended his work during the centuries when Europe had largely lost it. When his texts returned to Europe through Arabic translations in the twelfth century, they reset the intellectual agenda for centuries. Even today, the concepts he introduced—substance, essence, causation, potential, actuality, the mean—are woven into how educated people think and argue, often without knowing it.

He was, as Dante put it, simply: the master of those who know.