 Comparison of Hobbes’s view to Zabarella’s and other more fully Aristotelian ones is complicated by Hobbes’s thinking that all causes are efficient causes and that motion is the cause of all change in the natural world. In a more fully Aristotelian picture, explanations are causal, but causes can be of several sorts. Hobbes’s picture is more restrictive: to find the causes is to find the efficient causes. Moreover, he thinks the efficient causes are all motions, so the search for causes becomes the search for motions and mechanisms.