ABSTRACT
Consciousness is disturbed in various psychiatric conditions and so it is necessary for the examiner to evaluate its level during psychological testing or psychiatric diagnosing. Aristotle in his treatise On Sleep of his book Parva Naturalia deals with the subject more by discussing wakefulness than directly about consciousness. In some cases, he is more exact; he describes loss of consciousness in persons who have fainted or have received blows to the neck. He also refers to epilepsy as characterized by loss of consciousness similar in a way to that of sleep. Otherwise, he clearly states that sleep is a different condition than disturbances in which there is unconsciousness of the form seen in asphyxia, or when a person falls into a deep trance and is considered dead. In On Dreams Aristotle shows his remarkable ability of approaching intrapsychic phenomena. He first examines which faculties are involved in the creation of dreams.
