Epictetus

Epictetus was a Greek Stoic philosopher who was born a slave and became one of the most influential moral teachers of the ancient world. His philosophy, recorded by his student Arrian in the Discourses and the Enchiridion, is built on a fundamental distinction: between what is "up to us" (our judgements, intentions, and responses) and what is "not up to us" (everything external). This dichotomy of control, worked out with striking psychological depth, has found renewed interest in modern cognitive therapies.