Although sleep is one of the few shared activities common to all humanity, it is also the most private. What we experience during our sleeping hours is untranslatable during the daylight.
The way we sleep depends upon time and place, especially latitude. The view depicting in movies of our prehistoric ancestors huddled together for warmth and safety from predators in the communal cave as soon as the sun set is probably not far from the mark as the same basic pattern can be found, in a more sophisticated fashion, in Anglo-Saxon and Viking settlements, where all members of the clan would sleep on a raised parapet above a sunken, blazing fire in the Great Hall of a powerful chieftain, who would nevertheless sleep amongst his subjects. In the fortified keeps and castles of the later medieval period in Ireland and Britain elements of social stratification can be seen as now the presiding figures that controlled life within the castle have their own separate bedchambers.
Great changes in societal patterns were occurring in the city states of what is now Italy. A benevolent climate where the amounts of daylight and night-time are more equally distributed throughout the year led to lives less overwhelmed by the struggle for mere survival and the flourishing of the first recognizable modern cities. From these states came merchant princes and an artisan middle class involved in completely new professions. At night the streets were lit and families lived more spaciously in single family dwellings. As lives were less arduous it was no longer necessary to retire as early or to rise at dawn. It is a curious fact that the two presiding genius of the Renaissance, Michelangelo and Leonardo Da Vinci slept for less than four hours a night.
From this point onwards Western society was bent upon colonizing the night. With electricity the conquest was completed. Whereas candlelight and oil lamps seemed to re-enforce the nature of the surrounding night, electricity completely dispels darkness, replacing it with an artificial daytime. Soon the traditional conceptions of diurnal night and day will have no meaning, instead we have a twenty-four hour neuter-time that neither begins or ends. Technical acumen has made possible the manufacture of machines, robots and computers, whose main selling point is that they never tire, never sleep and never stop.
Increasingly prevalent in the work-driven and success haunted West is the idea that sleep is an enemy, only enjoyed by the idle and unambitious. Go getters only unwillingly submit to a hopefully dreamless sleep when absolutely required to preserve sanity, and even then for the shortest period possible. Upon waking the inexplicable images that the helpless dreamer witnessed are dispelled by the light of the working day and dismissed as irrelevant. Are we too far off a time when a sleep deprived scientist, every hour ridden by waking nightmares re-engineers and genetically alters an unborn child so that it will never sleep? And when that happens can we consider that person who, having never experienced nightly oblivion, that plunge into an endless ocean where unremitting self-consciousness is blissfully, if only temporarily relinquished, human at all?