Tony Crisp Interpretation:
Aristotle deals with the subtleties of sleep and dreams in three great treatises—De Somno et Vigilia; De Insomnis; and De Divinatione Per Somnum (On Sleep and Dreams, On Sleeping and Waking, and On Divination Through Sleep). The views on dreaming are developed out of Aristotle’s concepts of mind and imagination, and his observation of how people deal with sleeping and waking. For instance, he saw imagination as the result of sensory and subjective perception occurring after the disappearance of the sensed object, recognizing that the human mind can form powerful and realistic “afterimages” of things no longer present. Aristotle carried this insight into the realm of sleep and applied it to dreaming. He added to this the observation that while awake we have the easy ability to distinguish between what is an external object and what is our imagined object. In sleep, however, this faculty disappears or is almost completely absent. This produces the sense of enormous reality we have in dreams, and the feeling that we are facing actual events and people. It is what Freud called the hallucinatory property of dreams. See .