This collection of essays extends the microgenetic theory of the mind/brain state to basic problems in process psychology and philosophy of mind. The author's microtemporal model of brain activity and psychological events, which was originally based on clinical studies of patients with focal brain damage, is here extended to such topics as the concept of the moment in Buddhist philosophy, conscious and unconscious thought, the nature of the self, subjective time and aesthetic perception. The author develops a highly original psychology of mental process, actually a 'cognitive metaphysics', which is grounded in brain physiology and clinical psychopathology. A central theme is that the natural categories that arise in the extensibility of temporal data are continuous with conceptual structures in the human mind.