Cato’s early Stoic training was as hard and uncompromising as he hoped to become. He walked around Rome in unusual clothing with the goal of getting people to laugh at him. He learned to subsist on a poor man’s rations. He went barefoot and bareheaded in heat and rain. He learned how to endure sickness in perfect silence.

What was the point? Pain and difficulty could build endurance and self-control. Cato was drilling himself to become indifferent to all things outside the magic circle of the conscience. He could be ridiculed, starving, poor, cold, hot, sick—and none of it would matter. As the Stoic philosopher Epictetus taught: “Where is the good? In the will. Where is the evil? In the will.”

All of Cato’s practice paid off. Seneca, the great imperial Stoic, relates a telling story. Visiting the public baths one day, Cato was shoved and struck. Once the fight was broken up, he simply refused to accept an apology from the offender: “I don’t even remember being hit.”

For other lessons from Cato, read our article “Stoicism For Modern Stresses”