Nicomachean Ethics is the name normally given to Aristotle's best known work on ethics. It plays a pre-eminent role in defining Aristotelian ethics.It consists of ten books, originally separate scrolls, and is understood to be based on notes from his lectures at the Lyceum, which were either edited by or dedicated to Aristotle's son, Nicomachus. The theme of the work is the Socratic question which had previously been explored in Plato's works, of how men should best live. It is widely considered one of the most important historical philosophical works, and had an important impact upon the European Middle Ages, becoming one of the core works of medieval philosophy.

Aristotle was a Greek philosopher and scientist born in Stagirus, northern Greece, in 384 BCE. His father, Nicomachus, died when Aristotle was a child, whereafter Proxenus of Atarneus became his guardian. At eighteen, he joined Plato's Academy in Athens and remained there until the age of thirty-seven (c. 347 BCE). His writings cover many subjects – including physics, biology, zoology, metaphysics, logic, ethics, aesthetics, poetry, theater, music, rhetoric, linguistics, politics and government – and constitute the first comprehensive system of Western philosophy. Shortly after Plato died, Aristotle left Athens and, at the request of Philip of Macedon, tutored Alexander the Great between 356 and 323 BCE. According to the Encyclopædia Britannica, "Aristotle was the first genuine scientist in history. ... Every scientist is in his debt."