I just caught myself falling asleep (literally) and once again found myself musing upon this habit, which in fact I indulge in every night. (I never have trouble sleeping. I once literally slept through a building being demolished, well within earshot.)
I can't help feeling that sleep is not only a biological but a mental, almost a logical necessity. Tonight, as so often when I wake up just as I was about to slide into slumber, I caught myself about to pass the portal of a dream. It was set in a dark cinema, and had something to do with staring down some glowing white shaft that opened onto another reality. Unearthly as it was, this shaft was regarded with some familiarity by myself and by the other people present in the dream.
Can you imagine a life that was all wakefulness? Can you imagine day passing into day without an intervening period of unconsciousness, dreams and irrationality? Can you conceive human existence without the punctuation of sleep? Can you imagine a mental stream formed entirely of reason, logic and judgement, without the nightly descent into irrationality and cognitive chaos?
I can't. Or, insofar as I can, it seems a deeply depressing and disturbing idea.
The nightly unclenching of the mind doesn't seem merely like a biological accident, but a necessary condition of mental life. It is as though the order, structure and sequence of waking thought is a sort of artificial construct that is imposed, temporarily and with great effort, upon an underlying flux of free-wheeling concepts, sensations and atmospheres, one to which we gratefully return every sixteen hours or so. I genuinely feel (and I don't mean this in a smart-alecky way) that the mental world of the sleeper is more primal, even in a sense more real, than the mental world of the waking man. Of course, the world of the waking man is more real in a very solid sense; if you shoot a man who is sleeping in bed, you will kill or injure him. But the world of the dreamer seems more real in a different sense; in the sense that it is closer to our intuitions and our undisciplined emotions our and deepest desires. Dreams are closer to the reality, not of the physical world, but of the mental world; and we never directly inhabit the physical world, as we do the mental world.