On the Motion of Animals

This text is Aristotle’s general principles on the motion of animals. Aristotle attempts to combine a physiological explanation of animal locomotion in terms of spirit or pneuma and with a psychological account in terms of desire and thought, which also includes imagination and perception. He thinks it possible to account for animal movements purely in terms of the physical events taking place in the body, while at the same time he wants to explain action, at a philosophical or analytical level, by way of the interaction of desires and beliefs.