August 20, 2026

Your Own Momentum

When you push a cylinder, you give it the beginning of its motion, but not the capacity for rolling. So too an object that presents itself to us produces an impression on our mind, but the assent is in our own power.

Chrysippus of Soli, who led the Stoic school in the third century BCE and shaped much of its logic, used this image to answer critics who claimed that a fated universe left no room for human responsibility. In this argument, preserved by Cicero in On Fate, he compared an outside event to the shove that starts a cylinder rolling down a hill. The shove sets the motion going, but the cylinder rolls in its own particular way because of its own shape and nature, and so it is, Chrysippus argued, with a person struck by circumstance: the event triggers a response, but the character of that response comes from within. This is the heart of how Stoicism treats obstacles: what happens to us often arrives like an unplanned push outside our control, but the shape of our reply, steady, clever, honest, is entirely ours to make. Every obstacle, then, becomes less a wall and more a chance to show, through our own rolling, what we are actually made of.

A principle of Stoicism: The Obstacle Is the Way →