The Psychology of Sleep

Sancho Panza says: “Now, blessings light on him who first invented sleep! Sleep which covers a man all over, thoughts and all, like a cloak; and is meat for the hungry, drink for the thirsty, heat for the cold, and cold for the hot. Sleep is the current coin that purchases all the pleasures of the world cheap, and the balance that sets the king and shepherd, the fool and the wise man, even.”—“Don Quixote.”

Sleeping is the one thing that everyone practices almost daily all his life, and that, nevertheless, hardly anyone does as well as when he began. We have improved in our walking, talking, eating, seeing, and in other acts of skill and habit; but, in spite of our experience, few of us have improved in sleeping: the best sleepers only “sleep like a child.” It must be that we do not do it wisely, else we should by this time do it well.

Even the race of mankind as a whole does not seem to be able to use sleep, to summon it, or to control it any better than primitive man did. We talk much of the need of sleep, and sagely discuss its benefits, but we know neither how to use the faculty of sleep to the best advantage nor how to cultivate it.

Yet for ages men have studied the mystery of sleep. We have acquired many interesting facts concerning its variation, and have formulated a number of theories concerning its cause and advantages; nevertheless, science has given us little real knowledge of sleep, and less mastery over it.

Mankind has had idols ever since consciousness began. Advancing knowledge has changed the nature and number of the idols, but it has not destroyed them. The idol of the present age is “Science,” and men worship it in the degree that it seems to fit their needs. They forget that Science is merely the knowledge of things and persons, arranged and classified, so as to make it available. In its nature it is fallible, for some new phase discovered to-day may show that yesterday’s conclusion was formed from a theory which itself was based on a mistaken premise. Man has caught a glimpse of something that resembled truth, has stated it, reasoned about it, and finally either established its authority or disproved it utterly through the discovery of the real thing he was seeking. Either result was progress, because man grows, as Browning says, “through catching at mistake as midway help, till he reach fact indeed.” So there is no need to be disturbed by the conflicting opinions of men of science touching the purpose or method of sleep. Even the rejected theories have added to the sum of our knowledge, and the field for investigation is still open to all who are faithful in noting and comparing the manifestations of Nature, which the scientists call phenomena.