Sleep is a distress purchase in the modern world. Like filling up with petrol or going to the dentist, it is an unacceptable interruption in the life of getting and spending. The very idea of the 24/7 society is predicated partly on the idea that people should be free to sleep when they like, but also on the underlying suspicion that they can do without it. There is a macho culture of sleeplessness - sleep is for wimps who can't take the pace. The tough and the motivated like to brag about how little sleep they need.
This is all expressive of the most characteristic contemporary delusion - the belief that we can conquer or, at least, improve on nature. Dazzled by the ubiquitous evidence of our ability to alter the world, we fall into the trap of believing we can effect equally radical changes within ourselves. Perhaps, one day, we shall succeed. But the changes we have imposed on the world are at least as malign as they are benign. Changes to ourselves are certain to be just as ambiguous.
Paul Martin's Counting Sheep is a bracingly clear and thoroughly researched refutation of this contemporary vanity. Everybody needs approximately eight hours of sleep a day. To lose even an hour or two has a disastrous impact on our health and effectiveness. Those who brag that they can manage on five hours or less are building up a sleep debt that they will one day have to pay in the form of serious mental or physical disorder. And why they should thus brag is, in any case, a mystery, because, as Martin happily affirms, sleep is not just good for us, but also profoundly pleasurable. Those, for example, who have not cultivated the art of lucid dreaming - dreams in which we know we are dreaming and can alter the course of events - are missing out on one of the most extraordinary and creative gifts of nature.
Perhaps the sleep issue is made more irritating to the contemporary imagination because it remains scientifically indecipherable. We don't really know why we must sleep - although there are many theories - and we certainly don't know why we dream. At least when we buy petrol, we know that it keeps the car going. But going to bed, unless it is to have sex, is an incomprehensible activity that offends our utilitarian minds.
Yet, though it is incomprehensible, there is much to be said about sleep, and Martin says most of it. This book is a masterpiece of efficiently and entertainingly delivered information. If you want to know about the unihemispheric (half-brain) slumbers of dolphins, the appalling disease of FFI - fatal familial insomnia - or all the mysterious layers of sleep through which we pass nightly, then you will find no more brisk and intelligible account.
The problem is, as Martin notes, that sleep, until quite recently, has simply not been taken seriously. A study in the 1990s revealed that British medical undergraduates spend no more than five minutes studying sleep, rising to 15 minutes in preclinical training. And the dangers and miseries of sleep apnoea - from which your reviewer suffers - have been understood and acknowledged only in the past few years. The belief that the condition in which we spend one-third of our lives is unimportant, or even wasteful, is deeply embedded in our culture.
It was not always so. Martin employs some very well chosen literary sources to demonstrate how highly sleep has been prized in the past. "God bless the inventor of sleep," said Sancho Panza, and an entire anthology could be composed of Shakespeare's exquisite hymns to sleep.
Significantly, our downgrading of sleep seems to be a direct result of modernity. People began to sleep less as coffee became more widely available. They could thus disguise their weariness by regular doses of caffeine. And then - disaster - came the invention of the light bulb by Edison in 1879. This disrupted nature's most obvious signal that we should go to bed - darkness - and confused all our body clocks. As a good modern man, Edison used to make much of his ability to do without sleep. But, also as a good modern man, he was lying. He was a compulsive napper.
Naps, in fact, seem to offer salvation. A well-ordered nap has the power to offset most of the worst effects of sleeplessness. Twenty minutes seems to be the minimum; anything less may make things worse.
But it is probably not enough to sell sleep to the tired modern by telling him that he needs it. Martin sees this, and provides a compendious celebration of the delights of sleep. He tells us how to cultivate lucid dreams, he rhapsodises about beds through the ages and he provides pages of scientific evidence for how much better life is with plenty of sleep. For example, we seem to replay in sleep - not necessarily in dreams - things we have learnt during the day. So, for example, if you have learnt to ride a bike, your sleeping brain will run through the neural activity associated with the muscular movements and, thereby, lodge them in your memory.
But the killer point, the one that really puts our modern obsession with staying awake into perspective, comes from Nathaniel Kleitman, "the great pioneer of modern sleep science". He was asked to explain the role of sleep. He replied that he would do so if somebody would first explain the role of wakefulness. Exactly. What is so special about our conscious tinkerings? Asleep, we can at least do no harm. And if we follow Martin's wise injunctions, we may well be able to do some small quantity of good.
Bryan Appleyard's most recent book is Brave New Worlds (HarperCollins)