ArgumentThis paper argues that Samuel Clarke's account of agent causation (i) provides a philosophical basis for moderate voluntarism, and (ii) both leads to and benefits from the acceptance of partial occasionalism as a model of causation for material beings. Clarke's account of agent causation entails that for an agent to be properly called an agent (i.e. causally efficacious), it is essential that the agent is free to choose whether to act or not. This freedom is compatible with the existence of conceptually necessary connections. Hence, Clarke can harmonize God's freedom of choosing with the existence of eternal and necessary relations among things. Moreover, in Clarke's account, only intelligent entities can be properly understood as efficacious causes. Beings deprived of intelligence are not agents or efficacious causes at all and their effects are thus the result of the immediate action of some intelligent being operating upon them.