17 FEBRUARY 1917, Page 9

SLEEP.

WHAT is, sleep? Nobody knows. Every human being ex- periences it, and therefore knows-it at first hand ; yet no one has yet understood it or explained it, from the point of view of the waking consciousness. We do not know what it is. Perhaps we never can know, any more than we can know what life is. We ourselves being alive, life is too close to us to be understood, as a mountain cannot be seen while we are on it, and as we cannot lift ourselves by pulling at our own boot-straps. To understand a thing is to have it explained by comparing it with some better-known thing ; but there is nothing better known to us than life, so we cannot explain it or understand it. A curious paradox ! And it may be so with sleep.

It used to be said that sleep's physiological equivalent was a diminution of blood in the brain. But this is now disproved, both by direct examination of the retina and by the ingenious method of balancing a man's body so that his heed rises if it gets lighter by being drained of blood, and vice versa. It is found sometimes that there is actually more blood in the brain during sleep than during the waking hours ; though this is perhaps exceptional. Still, if it happens at all, it disposes of the theory that sleep is simply an affair of cerebral anaemia. Other men of science talk of highest-level, middle-level, and lowest-level brain centres, the first-named being concerned with abstract thought, the second with perception, and the third with the organic processes such as circulation and respiration. But all this is hardly more than a using of words to cover our ignorance. Even if we know, or have reason to believe, that normal consciousness is specially linked up with certain areas of the cortex, we are none the less ignorant of what happens in those areas when consciousness is obliterated in sleep. On the physiological side, science has little or nothing to tell us.

Psychologically and metaphysically there is more to be said, with the help of material analogies. Life at its lowest, in amoebae and the like, is almost certainly unconscious, or nearly so. It is asleep. As we rise in the scale of physiological complexity, finding great differentiation of function and a continually extending system of nerves, we find also a continual increase of consciousness, as in the horse, elephant, man. These higher beings have reached the highest point of wakefulness that we know ; though they have to sink back into the earlier sleep-state every night, to recuperate their energies. This sinking back into the primary state seems to bring them once more in touch with some great and mysterious source of power. We do not know how it comes about, but we do know that sleep is immeasurably more refreshing and invigorating than any amount of mere resting. There is a difference in kind, not only in degree. Sleep is absolutely essential to life as we know it at present. The highest beings now known to us are in an alter- nating or oscillating condition ; taking in energy at night from somewhere deep down at the roots of Nature, and expending it in the furtherance of their conscious aims during the day.

But there is some ground for believing that this alternation or oscillation is not a final state. Almost all religions have taught an evolution out of time into eternity, an eternity of uninterrupted consciousness, a waking up finally and for ever. " There shall bo no night there." And it would be dangerous to dismiss this thought without respectful consideration, for it is hardly likely that the unanimous intuitions of so many wise and holy men can be alto- gether devoid of truth. And however the different religions may vary in matters of minor doctrine, there is a deep consensus on this matter of eternity. Even Buddhism has its Nirvana, which is far from being the annihilation which the earlier Western scholars thought it to be ; it is only the annihilation of time, of passions and the like ; it is Heaven under another name. It is the same with Hindu Vedanta and with Chinese Taoism : a third stage is

postulated, after the stage of alternate sleeping and waking—a stage which transcends both, but which we can best understand as a waking to a higher form of life. It is indeed probable that those who have mystical experiences—as when Paul was caught up into the third Heaven—may be momentarily carried forward into that stage, as when a very young child begins to wake from its pre-natal sleep. Perhaps we are all really children, and the mystics are the first to begin waking up. And when they tell us what they have seen, we cannot believe them ; we want to see for ourselves. Well, no doubt we shall, some day. Meanwhile we must rest content with faith, which is the assurance of things not seen.

Here we are brought into the kingdom of the poets, who, after all, are true seers and revealers in their way. What then do they say about sleep and its problems ? It is perhaps to be expected that they have a good deal to say on the subject, for a very active mind is likely to be a wakeful one, and geniuses no doubt often have bad nights ! Tho little girl said, trying to explain why she could not sleep, that she couldn't make her mind sit down ; and the poet will suffer from a like disability. Anyhow, the greatest of all—Shakespeare—writes about sleep in such an exceptionally wist- ul way thatthe autobiographical character of some of the passages is unmistakable. For example, that magnificent soliloquy and evoca tion of King Henry IV. in Shakespeare's finest historicalplay Sleep, gentle sleep,

Nature's soft nurse, how have I frighted thee,

That thou no more wilt weigh my eyelids down, And steep my senses in forgetfulness ? Why rather, sleep, liest thou in smoky cribs, Upon uneasy pallets stretching thee, And husb'd with buzzing night-flies to thy slumber, Than in the perfumed chambers of the great, Under the canopies of costly state, And lull'd with sounds of sweetest melody ?

0 thou dull god, why lost thou with the vile In loathsome beds, and leo.v'st the kingly couch A watch-case or a common larum-bell ?

Wilt thou upon the high and giddy mast

Seal up the ship-boy's eyes, and rock his brains In cradle of the rude imperious slugs, And in the visitation of the winds,

Who take the ruffian billows by the top,

.mg their monstrous heads, and hanging them

With earning clamours in the slippery clouds, That, with the hurly, death itself awakes ?

Canst thou, 0 partial sleep ! give thy repose To the wet sea-boy in an hour so rude ; And, in the calmest and most stillest night, With all appliances and means to boot, Deny it to a king ? "

Matthew Arnold considered the last thirteen lines of this monologue to be an example of the very finest poetry ever achieved in any language. The same sentiment is repeated in Henry V., but in less imaginative language (Act IV., Scene i.), though here also the poet is probably thinking of himself as well as of the King, and is wondering over the curious paradox that the great and powerful, of whatever kind, are full of care and far from happiness, while the man of mean estate and powers, " with a body fill'd and vacant

mind," gets him to rest and sleeps in Elysium.

Another famous sleep-reference is that in Macbeth, when the

Thane of Cawdor, fresh from Duncan's murder, rejoins his wife and instigator

Methought I heard a voice cry, ' Sleep no more I Macbeth does murder sleep !' the innocent sleep; Sleep, that knits up the ravell'd delve of care, The death of each day's life, sore labour's bath, Balm of hurt minds, great nature's second course, Chief nourisher in life's feast."

The "ravell'd sleeve" is not a sleeve, though it might be supposed so by fishermen who wear knitted jerseys. It means a tangled or knotted skein of silk ; the word " sleeve " being allied to the " sliver " of the spinning mills, and both derived from a Scandinavian root, cognate with the German "Schleife," a loop, slip-knot. No doubt "sleeve" and "sleeve" can be traced originally to the same idea of slipping, but certainly Shakespeare was thinking of a loose and tangled mass of floss-silk, in the confusion of which no thread can be followed far, somewhat as, in a tired and confused mind which is in want of sleep, no single line of thought can be followed out, and all seems confused and orderless. Probably, however, the most familiar quotation about the recuperative virtues of sleep is not Shakespeare's but Young's; for most of us are familiar,

from our youth up, with the line—.

" Tired Nature's sweet restorer, balmy sleep ! "-

which is the first lino in Night Thoughts.

Southey must have been a worse sleeper than Shakespeare, for while the latter finds sleep the balm of hurt minds, the former says- " Thou hest been called, 0 sleep ! the friend of woe ; But 'tis the happy that have called thee so"; and indeed it is true enough that the difficulty of hurt minds, and woeful people in general, is that they cannot get the sleep which is needed. Contentment is a prerequisite. Sancho Panza invoked blessings on the man that first invented sleep ; but Sancho was well and jolly, and could make good use of the invention. Probably Don Quixote slept very badly, for he had a hurt mind in more senses than one.

Of Biblical sleep-references the number is seventy-two. One of the most frequently quoted is that in Psalm cxxvii., rendered " he giveth his beloved sleep" in the Authorized Version, and similarly in the Revised Version—" he giveth unto his beloved sleep?, As a matter of fact, however, the correct rendering is " he giveth unto his beloved in sleep "—meaning either bodily refreshment, or, more probably, inspiration of spirit. It was a universal belief in early times that God revealed Himself or gave help and counsel in the sleep of His worshippers, as with Abraham in Genesis xv. 12. In the Greek classical period it was customary for sick people to sleep in the temple of Aesculapius, in order that the god might prescribe to them in dream. Pinder says-

" For oft in sleep comes light upon the soul, But in the day their fate is hid from men "- and Shelley echoes it in " Mont Blanc' - " Some say that gleams of a remoter world Visit the soul in sleep "- while Dante undoubtedly had sleep-visions or trance-experiences which provided him with at least a basis for his poem.

It is a curiously common notion among poets and seers that, as already suggested, sleep is only a sleep within a sleep, our normal waking being also sleep, regarded from a higher point of view. No doubt the phenomena of dreams led man to wonder at a very early stage which was real—the sleeping or the waking life--if

indeed either ; as the Chinese sage quaintly says :- "Once upon a time, I, Chuang Tzu, dreamt I was a butterfly, Guttering hither and thither, to all intents and purposes a butterfly. I was conscious only of following my fancies as a butterfly, and was unconscious of my individuality as a man. Suddenly I awaked, and there I lay, myself again. Now I do not know whether I was then a man dreaming I was a butterfly, or whether I am now a butterfly dreaming I am a man."

Shakespeare similarly saw that things are not necessarily what they seem, for in Prospero's famous speech he says that we are such stuff as dreams are made of ; though he does not speculate as boldly as Chuang Tzu, who goes on to say that when we wake up after death we may regret having clung to life—as the lady Li Chi regretted her weeping and reluctance when she found that being marricd was not so bad after all ! To quote Shelley again, we find the same idea in " Adonais " :- " Peace, peace ! he is not dead, he doth not sleep I He hath awakened from the dream of life, 'Tis we who, lost in stormy visions, keep With phantoms an unprofitable strife."

These are good thoughts to keep before us in these terrible days. Life here is probation, an educative discipline. But we shall wake out of our bad dream by and by, and we shall have learnt things from it. It was somehow necessary, but it was only a phase. The seen things arc temporal, the unseen things eternal.

J. ARTHUR HILL.