Most of us believe that we sleep in order to rest our tired bodies and minds. This centuries-old common-sense view is challenged by Meddis, who describes and argues for a controversial new theory of the nature and function of sleep. The theory seeks to replace the old view with the idea that sleep may no longer serve any important function in modern man. Whereas the sleep instinct helps animals to survive by driving them to hide away for as long as possible each day, this is no longer a valuable asset in civilised surroundings. Nevertheless, we still feel driven by a primeval urge beyond conscious control to crawl away every evening to the security of our beds to wait out the dangerous hours of darkness which were such a threat to our ancestors. Contrary to contemporary wisdom, he also argues that dreaming is a primitive and particularly valueless kind of sleep - a crude and dangerous heritage from our reptilian ancestors which is kept to a bare minimum in most adult warm-blooded creatures...