Stoicism resembles Buddhism in its focus on practical psychology and mastery of the mind through reason. The Stoics do not deny the reality of the physical world and the ego, but they teach that unhappiness comes from attachment to undependable things, things outside one's own control. The Stoic road to happiness comes from training one's mind, through the application of reason, to care about nothing except one's own ethical actions, and the ultimate measure of a philosopher consists in successful application of this training, not in knowledge or argumentation.

There are glaring differences between Stoicism and Buddhism, of course. The Stoic definition of ethical behavior is not rooted in compassion like Buddhism is, for example, and the Stoics did not create a practice of mental training anywhere near as well-elaborated as Buddhist meditation.