Sleep as a model for mental illness
Sleep is a normal state that contains within it another normal state, dreaming. Dreaming shares with so-called “mental” illness the formal properties of psychosis (hallucinations and delusions) and is, by definition, a delirium (because it manifests visual hallucinations, disorientation, memory loss, and con- fabulation). So sleep is at the very least a model for mental illness. But sleep is certainly more than a model because it makes us think about what mental illness may really be. In so doing, it makes some of us realize that the term “mental illness” is really a mis- nomer. If we were more critical and more philosoph- ical, we would substitute a definition like “diseases of the mind, the brain basis of which is not yet known.”