Stoic Physics: Logos, Fate and Providence

The Stoics believed ethics must rest on an understanding of nature, so they developed a detailed physics. Everything that exists, they held, is bodily, including the soul. The universe is a single living being, pervaded by pneuma, a fiery breath, and organized by logos, a divine reason that they also called God, Zeus or Nature. Because the logos orders everything, all events happen according to fate, a chain of causes, and this order is providential, working for the good of the whole.

The Stoics also taught that the cosmos periodically dissolves into fire and is reborn. If everything is fated, how can humans be responsible? Chrysippus argued that our actions still flow from our own character and judgments, a position later called compatibilism. A famous image compares a person to a dog tied to a cart: it can run along willingly or be dragged. This physics underpinned the Stoic ideal of living in agreement with nature.