In the act of self-observation, an individual becomes simultaneously observer and observed, subject and object. While some philosophical psychologists have dismissed thisreflexivity, the present author proposes that it isthe essential feature of the self, making it the basis of a new, conceptually simple, structural and dynamic theory of the self. Drawing from psychopathology, poetry and literature, the author portrays normal and disordered psychological states as disturbances in reflexivity. Qualitative and quantitative variations in this core function are proposed to define discreet spectra of psychological situations. The author briefly examines the theories and practices of psychoanalytic and existential psychology, and proposes clinical applications of the new views here depicted. He attempts to show that inherent limits to our simultaneous knowledge of both aspects of the reflexive duality limit the precision and validity of all psychological theorization.