This paper reviews the development of the microgenetic theory of the mind-brain state, its roots in genetic and process psychology, and its application to a variety of problems in neuropsychology and the theory of mind. The temporal or process perspective of microgenssis, its subjectivism, and its concept of actualization and internal relations are in sharp contrast to the substantialism, logical atomism, and theory of interaction by external relations that characterize much of cognitivist theory. It is my belief that microgenesis can help to bring neuropathological phenomena and inferred normal psychic processes into relation with process-based psychoanalytic formulations such as those proposed by paul schilder and Dovid Rapaport, among others.