Epictetus

The name Epictetus simply means 'acquired'. Born in Phrygia, he was a slave in Rome to a freedman of Nero and was lame, perhaps from a master's abuse. His owner let him attend the lectures of the Stoic Musonius Rufus, and after his freedom he began teaching himself. When Domitian expelled the philosophers in 93 CE he moved to Nicopolis in north-western Greece and ran a school there until his death.

Like Socrates he wrote nothing. His student Arrian took down his lectures and edited them as the Discourses and a short Handbook. The tone is direct, rough and often sardonic, constantly pulling students back from theory to practice: you have read Chrysippus, fine, but can you keep your temper when someone insults you?

The first sentence of the Handbook holds his whole teaching: some things are in our control and others are not. Judgement, desire and will are in the first class; body, property, reputation and office in the second. To stake happiness on what is not in your control is to guarantee misery; to attend only to your own judgements is to be beyond harm. Marcus Aurelius carried his book on campaign, and both Pascal and modern cognitive behavioural therapy drew from him.