Abstract
The relation between sensing/cognition and mental disorders (āfāt al-dhihn) receives special attention in Avicenna’s writings on psychology and medicine. Avicenna identifies two ways of diagnosing mental disorders: one way is in relation to the function of the senses, while the other is in relation to the internal faculties. A psychological phenomenon commonly exhibited in such disorders is the experience of hallucinatory content, that is, registering perceptible content that does not correspond to an existing object in external reality. In this paper, I set out to investigate the cognitive process underlying the experience of hallucinatory content, and to show the significant roles that compositive imagination plays in creating and imposing this content upon the sensory experience.