Previous analyses of descriptively defined psychotic phenomena have concluded that they can occur in benign spiritual experiences as well as pathological states. Attempts to forge a distinction between psychotic experiences in spiritual and pathological contexts on the basis of the form or content of the experience (broadly described) can be disproved by counterexample; distinguishing on the basis of negative or positive consequences of the phenomena for the individual can be seen to beg the question. In the present paper, it is argued that examining the fundamental conceptual organization of psychotic and mystical mental states not only elucidates the observed similarities between them, but can highlight the differences, and the processes by which negatively evaluated pathological features can be seen to emerge. Oriental philosophical systems such as Tibetan and Zen Buddhism, and Tantric Hinduism, provide conceptualizations of mystical states of mind, from which a model can be drawn, while the epistemologies of these systems provide an illuminating metaphysical perspective on both psychotic and mystical experiences. It is concluded that mystical and psychotic experiences can be distinguished not only by emotional and behavioral consequences, but by real differences in the states themselves; certain features, such as loss of subject/object boundaries and loss of the relative dimensional structure of perception, are common to both processes.