CHAPTER II

HOW MUCH SLEEP

Six hours in sleep, in law’s grave study six,

Four spend in prayer, the rest on Nature fix.

(Translation.) SIR EDWARD COKE.

Man is the highest expression yet discovered of the “living organism,”

and sleep has always taken more of his time than any other function.

Marie de Manacéïne of St. Petersburg, in her great book called

“Sleep,” says: “The weaker the consciousness is, the more easily it

is fatigued and in need of sleep; an energetic consciousness, on the

contrary, is contented with periods of sleep that are shorter, less

deep, and less frequent.” Although the consciousness of the race has

developed and strengthened enormously, and is steadily strengthening

itself, the old-fashioned idea that one-third of our time should

be spent in sleep holds the average mind as strongly as ever. We

insist upon it for the young, impress it upon everybody, and look

distrustfully upon him who is so daring and unreasonable as to say that

he requires less than eight hours of sleep. When an idea is intrenched

in the mind it is next to impossible to drive it out by reason or even

by repetition.

It is the popular belief that Alfred the Great—who is also Alfred the

Wise and Alfred the Good (being dead so long)—divided time into three

equal parts, and taught that one part should be given to sleep. If he

had said this, it would not follow that it is the last and wisest word

on the best way to divide our time, but he did not say it. What he

said was that one-third of each day should be given to sleep, diet and

exercise: that is, that a man should devote eight hours to sleeping,

eating and whatever form of exercise or recreation he desired.

There is nothing to show that Alfred spent even six hours in sleep,

although there is plenty of proof that he recognized the difference

between rest and sleep, for he gave the second division of the

day—eight hours—to study and to reflection, while the remaining eight

hours were to be for business. In those days kings worked hard. Sir

Henry Sumner Maine says that the list of places where King John held

court shows that even he was as active as any commercial traveler

nowadays. (“Early Law and Custom,” p. 183.)

But the superstition that Alfred recommended eight hours for sleep will

not down, and no amount of argument or proof will change the opinion

of the average man on this point. “Our forefathers slept eight hours,”

they say; “so should we.” We forget that probably the rushlight and

the candle had much to do with the long hours of sleep in olden times.

As artificial light has improved, sleeping-time has been shortened.

There is an old English quatrain which runs:

“Nature requires five,

Custom gives seven,

Laziness takes nine

And wickedness eleven.”

But sleep is a natural need, and, like any other natural need, varies

in degree in different persons. Dogs, cats and other animals generally

sleep more than we do, and their young ones sleep still more. Generally

speaking, the infant, whose mental powers have barely awakened, who is,

so far as we can tell, merely a human animal, needs more sleep than it

will ever need again in its existence. In this great need of sleep the

human animal resembles other animals.

It frequently happens that, as a man waxes older, he requires less and

less sleep than in his growing and most active years. But old people

who have outlived their mental life come to a time when they sleep and

perform merely the physical functions like the infant; so also with

those whose energy so far exceeds their physical strength that the mere

effort of living exhausts them. This condition may be in part due to

overstrain of the powers of youth and middle age, but it also follows

the fixed idea that years diminish strength and lessen energy. It is

easy to fall into this notion, for it accords so well with the general

idea that rest must come only after the period of activity, whether

that period be a day or a lifetime.

All of us have had periods when we have needed fewer than our average

hours of sleep. People who sleep out of doors or in thoroughly

ventilated rooms, under warm but light clothing, find that they need

less sleep than when they occupy poorly ventilated rooms and wrap

themselves in heavy, unhygienic clothing. Fresh discoveries are being

made almost daily by those who give intelligent consideration to these

things.

Even babies differ in their need of sleep. I know one healthy,

happy, beautiful baby who has never slept the average sixteen hours

that babies are supposed to need. This child is now between three

and four years of age, and has never gone to sleep before nine or

half-past nine at night. Her parents had the common idea of long

hours of sleep for infants, and the child had a hard struggle for a

while to convince them that she had no such need: such struggles are

often called “naughtiness.” She was regularly put to bed at seven

o’clock, and all the usual devices for enticing a baby to sleep were

practiced. Sometimes she was left severely alone, sometimes she had

gentle lullabies sung to her, but, whether alone or in company, this

particular baby played and enjoyed herself until between nine and

nine-thirty, when she quietly dropped to sleep. She awoke as early as

the average baby wakes, happy and refreshed, and her parents finally

learned that there is no sleeping rule that has no exceptions, whether

applied to infants or adults.

Drowsiness is a sign that we ought to sleep, just as hunger is a sign

that we ought to eat. Natural wakefulness means that we ought not to

sleep. The child tries to obey the promptings of nature, but we think

these promptings are wrong, if not wicked, and force him into all sorts

of bad habits. Says Michelet, “No consecrated absurdity could have

stood its ground if the man had not silenced the objections of the

child.” We are slowly learning that there is no need or function of the

body or of the mind that is exactly the same in all individuals, or

that is always the same even in the same individual.

But, in spite of this dawning knowledge, we still view with alarm any

disregard of the rule, either in ourselves or another; so true it is,

as Thomas Paine says, that “It is a faculty of the human mind to

become what it contemplates.” We have looked upon ourselves as having

certain, unvarying, imperative needs until we have almost become

subject to them.

The psychology of sleep · 第 2 / 54 章