This chapter analyzes free will in terms of a complex set of psychological capacities that agents possess and exercise to varying degrees, focusing on the capacities for imagination. To have free will is to possess these psychological capacities such that the agent is the author of his or her actions and can deserve credit or blame for them. To act of one’s own free will is to have had (reasonable) opportunity to exercise these capacities in making decisions and acting. There is a long philosophical tradition of treating free will as the set of capacities that, when properly functioning, allow us to make decisions that contribute to a good or flourishing life. On this view, free will is a psychological accomplishment. Free will also allows us to be the causal source of our actions in a way that is compatible with determinism and naturalism.