Epictetus was a Stoic philosopher who lived during the 1st and 2nd centuries CE in the Roman Empire. He was born into slavery in Hierapolis, in modern-day Turkey, but was permitted to study philosophy. After gaining his freedom, he taught in Rome until an imperial edict expelled philosophers from the city. He then established a successful school in Nicopolis, Greece, where he lived simply and taught until his death around 135 CE.

Though physically lame, the exact cause of his disability is uncertain, with ancient sources offering conflicting explanations. Epictetus wrote nothing himself; his teachings were recorded by his students, most notably the historian Arrian. His surviving works consist of the Discourses, a collection of his lectures, and the Enchiridion or Handbook, a concise manual of his core ideas compiled by Arrian.

His philosophy is intensely practical, focusing on achieving happiness through self-discipline. A central teaching is the distinction between what is within our control, such as our judgments and desires, and what is not, such as wealth, reputation, and health. According to his thought, true freedom and tranquility come from focusing exclusively on what we can control.

Epictetus is considered one of the most important Roman Stoics. His ideas significantly influenced the emperor Marcus Aurelius and later Christian thought. In modern times, his practical teachings have experienced a revival and are noted for their similarity to principles in cognitive-behavioral therapy.