Questions about the nature of causal relations occupy a central position in early modern philosophy. The prominence of this topic in seventeenth-and eighteenth-century thought can, in large measure, be traced to a specific historical problem: the need to reconcile an emerging scientific view of the natural world—mechanistic physics—with traditional beliefs about the relation between God and his creation. On the one hand, natural philosophers of the period see their task as one of identifying the underlying causal structures of observed phenomena and of framing explanations in terms of matter and motion alone. On the other hand, it is generally recognized that God is responsible not just for creating the world and its contents, but for sustaining them in existence as well. Against this background, in which philosophy, physics, and theology merge, the problem of causation arises in several contexts: in the realm of purely physical inquiry (how does one body produce changes in another body?); in regard to relations between the