Interactionism is the theory in the philosophy of mind which holds that, matter and mind being distinct and independent, they exert causal effects on one another. As such, it is a type of dualism. It can be distinguished from competing dualist theories of epiphenomenalism (which admits causation, but views it as unidirectional rather than bidirectional), pre-established harmony, and occasionalism (which both deny causation, while seeking to explain the appearance of causation by other means).