Hallucinations. In Middle ages they were explained by the spiritual brightening or, opposite, obsession by a devil. Ten of people were declared saints, thousands - burned out on the fires of inquisition.In our time them it is accepted to consider the sign of madness, to grave illness or by investigation of reception of narcotic facilities. But how so it?you firmly sleep in the room and suddenly wake up from a sharp ring in a door. Upstart, you go near a door, but nobody is present there. "Probably, appeared", - you think, not guessing that this was a typical hallucination. "What hallucination? I am not mad" in fact!In the new work Oliver Сакс calls to the world of hallucinations, and, as usual, the main value of book is presented by the real histories of people entering into a persistent fight for a return to the psychical health and valuable life!.