Almost everything people read of Stoicism today comes from three Roman-era writers. They lived very different lives: a wealthy statesman, a former slave and an emperor. Together they show Stoicism being practiced under pressure.

Seneca

Lucius Annaeus Seneca (about 4 BCE to 65 CE) was born in Corduba in Spain, became a famous writer and orator in Rome, and served as tutor and then adviser to the emperor Nero. He wrote essays (such as On Anger, On the Shortness of Life and On Providence), tragedies, and above all the Moral Letters to Lucilius, 124 letters of practical advice to a younger friend. In Richard Gummere's translation (1917 to 1925), the first letter begins: “Nothing, Lucilius, is ours, except time.” Letter 13 observes: “There are more things, Lucilius, likely to frighten us than there are to crush us; we suffer more often in imagination than in reality.”

Seneca is also controversial. He grew enormously rich while preaching simplicity and served a ruler who committed terrible crimes. Critics in his own time called him a hypocrite; Seneca replied that he spoke of virtue as one still striving toward it. In 65 CE, accused of joining a conspiracy, he was ordered by Nero to take his own life, and ancient historians describe him meeting death calmly.

Epictetus

Epictetus (about 50 to 135 CE) was born in Hierapolis in Phrygia (in modern Turkey) and grew up enslaved in Rome, owned by Epaphroditus, a powerful freedman at Nero's court. His name simply means “acquired.” He was allowed to study with the Stoic teacher Musonius Rufus, and was later freed. Tradition says he was lame, perhaps from mistreatment. When the emperor Domitian banished philosophers from Rome late in the first century, Epictetus moved to Nicopolis in western Greece and founded a school.

He wrote nothing himself. His student Arrian recorded his lectures as the Discourses and compiled the short Enchiridion. His teaching is blunt, funny and demanding. Having known slavery firsthand, he insisted that no one can enslave the will: a tyrant can chain the body, but cannot force us to judge or choose against our will.

Marcus Aurelius

Marcus Aurelius (121 to 180 CE) was Roman emperor from 161 to 180 CE. His reign saw long wars on the Danube frontier and a devastating plague. He thanks his teacher Rusticus for introducing him to the recorded lectures of Epictetus. Often in army camps, he wrote private notes to himself in Greek. These became the Meditations; the ancient title is usually rendered To Himself. They were not written for publication.

In George Long's translation (1862), Book 2 opens with a morning exercise: “Begin the morning by saying to thyself, I shall meet with the busy-body, the ungrateful, arrogant, deceitful, envious, unsocial.” Marcus goes on to remind himself that such people act from ignorance of good and evil, that they are his kin, and that we are made for cooperation, like hands or feet working together. Elsewhere he writes: “The universe is transformation: life is opinion.”

Historians note tensions in his life too: a philosopher who prized gentleness also fought long wars, Christians were martyred under his rule, and he chose his son Commodus as successor, a choice widely judged a disaster.

Musonius Rufus

Epictetus' teacher deserves a mention. Musonius Rufus argued, unusually for his time, that women should study philosophy, as they share men's capacity for reason and virtue. He also stressed practical training: simple food, hard work and endurance. Sometimes called the Roman Socrates, he was exiled more than once for his outspokenness.

Worked example: three Stoics facing hardship

Each of the Roman Stoics met serious misfortune, and comparing their responses shows how one philosophy took different shapes in different lives.

Seneca in exile. In 41 CE the emperor Claudius banished Seneca to the island of Corsica, where he stayed about eight years. From exile he wrote a consolation to his mother, Helvia, arguing that a change of place cannot take away what truly belongs to us: our virtue and our minds, which are free to roam the whole universe. Seneca's style is literary and personal; he consoles by reasoning with someone he loves.

Epictetus and banishment. Epictetus, who had already known slavery, was expelled from Rome with other philosophers. His response was characteristically blunt. In the Discourses he imagines a tyrant threatening to chain him, and replies, in effect, that the tyrant may chain his leg, but not even Zeus can overpower his will. He then simply moved and built a famous school in a new city.

Marcus amid war and plague. Marcus Aurelius faced not exile but the crushing duties of power: frontier wars, plague, and the rebellion of a trusted general in 175 CE. His notes keep returning to the same few medicines: do the task in front of you, treat others as kin, and remember how brief all things are.

Notice the shared core. All three distinguish what fortune can take from what it cannot, and all three find in that distinction a reason to keep acting well. Notice also the differences in voice: Seneca the warm letter writer, Epictetus the tough teacher, Marcus the self-questioning ruler. Readers today often find that one of the three speaks to them more than the others.