This article traces the philosophical idea of self-perception from the times of ancient Stoicism to the thirteenth century by analyzing the views of Seneca, Augustine, and Olivi. The central argument is that they defend the same idea according to which self-preservation and the appropriate use of one’s body requires awareness thereof, despite the obvious contextual differences and the uncertainty of direct historical connections between the authors. They think that this kind of self-awareness does not belong only to human beings, because irrational animals need to perceive their bodies, the functions of their bodily parts, and to perceive themselves as living beings in order to act appropriately and survive. The attribution of self-perception to animals is based on a distinction between the experiential awareness of the soul and the intellectual understanding of its essence, a distinction postulated by all three authors. The philosophical affinities between their views show that ideas that originate in Stoic thought were transmitted, directly or indirectly, to medieval philosophical psychology.