Dunamis and the Science of Mechanics: Aristotle on Animal Motion

It is shown that Aristotle's references to automata in his biological treatises are meant to invoke the principle behind the ancient conception of the lever, i.e. that points on the rotating radius of a circle all move at different speeds proportional to their distances from the center. This principle is mathematical and explains a phenomenon taken as whole. Automata do not signify for him primarily a succession of material movers in contact, the modern model for mechanism. For animal locomotion and embryological development, Aristotle models his dunamis concept on the idea of mechanical potential that the lever principle displays.