Abstract
This chapter considers the ways in which Leibniz sought to attack the occasionalists commitment to the existence of passive created substances. While considerations of the activity and passivity of created substance may not have yielded success for Leibniz, people should not think that these are the only ways in which considerations of the notion of substance fed into Leibniz's rejection of occasionalism. Given that all of his opponents were Cartesians who held that the passivity of matter was a consequence of the fact that its nature was extension, the position was also open to attack via a critique of the notion of extended substance as well. In offering empirical arguments for the claim that substances are essentially active there is clearly a sense in which Leibniz was arguing against the existence of passive substances. Leibniz himself seems to have conceived of occasionalism as a contemporary phenomenon. The term 'occasionalism' applies to a wide range of philosophical views.