In my article I evaluate Searle's account of mental causation, in particular his account of the causal efficacy of unconscious intentional states. I argue that top-down causation and overdetermination are unsolved problems in Searle's philosophy of mind, despite his assurances to the contrary. I also argue that there are conflicting claims involved in his account of mental causation and his account of the unconscious. As a result, it becomes impossible to understand how unconscious intentional states can be causally efficacious. My conclusion will be that if Searle's conception of unconscious intentionality is to play a genuine role in the causal explanation of human action, it needs to be rethought.