According to Plato, a man's soul is an immortal, immaterial entity distinct from the body, composed of three parts: the rational (reason), the spirited (anger and ambition), and the appetitive (desires). He believed that true learning is a process of anamnesis or remembering knowledge the soul possessed before being embodied. For an individual to be just and live a good life, the rational part of the soul must rule over the other two, which often involves the spirited part helping to control the appetites.