 According to the Stoics, inanimate objects like logs and stones are moved around from the outside. Animals, however, move themselves around. Animal motion has an internal source, the animal’s own mind, which is a material, bodily organ. The Stoics’ distinction between inanimate and animate motion is reminiscent of Lucretius’ distinction between the passive way inanimate objects are moved around, compared to the active motion of animals, which have libera voluntas and can move themselves around as they wish. The Stoics, however, believe that animals moving themselves around is compatible with the way in which animals move being causally determined. Animals move themselves when an impression occurs which arouses an impulse. For instance, a hungry dog may see a hunk of meat, and this arouses an impulse to run up to the meat and eat it. The impulse is triggered by the impression, but this is still a case of the dog moving itself toward the meat, not merely being passively pushed around by the impression.