Psychological determinism and rationality

There are arguments which purport to rebut psychological determinism by appealing to its alleged incompatibility with rationality. I argue that they all fail. Against Davidson, I argue that rationality does not preclude the existence of psychological laws. Against Popper, I argue that rationality is compatible with the possibility of predicting human actions. Against Schlesinger, I claim that Newcomb's problem cannot be invoked to show that human actions are unpredictable. Having vindicated the possibility of a rationally-based theory of action, I consider the form it might take.