APPENDIX CTHESE CLASSICAL, THOUGH ENTIRELY A PRIORI, THEORIES OF SLEEP ARE NOT WITHOUT INTEREST
ByGiovanni Argenterio(A.D.1556)
That it may well be difficult to explain the nature, differences, causes, and importance of sleep and waking, I think is made clear enough by the fact that concerning them there is great doubt and dissension among the highest philosophers and physicians. For Galen, when he questioned what sleep was, and what waking, decided at length that he could not be certain in what order of phenomena to classify them. Aristotle indeed, in his definitions of sleep and waking, arranges them in different places. Judging from selected books of all authors, no one, in my opinion, has been able to enumerate the general differences of sleep and waking by any certain method. Alcmœn thinks sleep is produced when the blood in the veins flows back and becomes congested. Empedocles believes it to arise from the chilling of heat in the blood. Diogenes states that sleep is induced by the blood pushing to the inner cavities of the body the air that is introduced into bodies. Plato and the Stoics taught that it arose of itself by the letting goof the spirit (or the releasing of the breath) and the consequent relaxation.
It is needless to refute the cause which Aristotle gives for sleep, and Galen for waking. They do not accord. The one thinks the true cause arises and has its seat in the heart,—the other in the brain. On account of which disagreement, great contention has been excited among more recent philosophers and physicians, as to which view to adhere to. Some attribute one significance, others another to these things. And so, because of the great difficulty introduced, there is nothing relative to the matter which is not in the deepest obscurity and doubt. A knowledge of this thing is, nevertheless, most useful, even if come upon by any other fortunate means, and not only through the knowledge of the doctors; by such means, for instance, as through the study of the general arts; for if it is joyful to philosophize, and to happen upon the hidden and abstruse things in the secret places of nature,—who would not find great pleasure in learning the causes of the sleeping and waking of creatures, why now they take long, now short sleeps; why at one time it is difficult to capture sleep,—at another time impossible to dispel it?
We wonder how at one moment sleep leads to waking; how waking and sleeping mutually succeed each other; why diverse things serve to explain each other, as sleep, waking,—and waking, sleep.
Sometimes these, sleep and waking, are injurious,—at other times beneficial. For sleep and also waking bring forth diseases, intensify them; both equally drive them away, soothe sorrows and likewise intensify them; by one and the other alike, morbid causes are often destroyed more effectually than by any other remedy; indeed, in conjunction with the benefit of these (sleep and waking), concoctions, food,purgatives, and finally all the functions of the different parts of the body may be exercised to the best advantage; nor is it possible, indeed, for a creature to live, or to maintain his life, without sleep and waking.
There is no action of the body or mind which has greater values to the body, nothing which supplies more reliable signs for discerning bodily ills, and showing how to be rid of them.
Of which things, indeed, the investigation and knowledge is most useful, and not without pleasure to those who delight in the understanding of things; that is what Aristotle, prince of philosophers, notices, when he writes his whole book concerning sleep and waking,—and often elsewhere at random in his writings. Not the less does Hippocrates notice them in his citations, for he wrote most sayings on the subject, so many that I omit them; and there are many in other books, of which a definite impression does not remain in my memory. But as I have said, when all, or certainly most writers on this subject may be perplexed with regard to these things, and involved in many difficulties, no one ought to condemn me, if, after them, and many men, I presume to write on this subject.
To refute the opinion of the philosophers concerning the causes of sleep and waking, I think superfluous; because, with Aristotle’s views surviving now many centuries, no authority among these other writers may be greater than his; and because the ignorant premises of the others makes all discussion of them become inane.
Because of this I think I should be excused for introducing the opinion of Aristotle among all the philosophers, that is, for choosing it from among them, for if we show it to be equally probable with the others which we presume to refute, it will be because, unlike them, it extinguishes them by its own plausibility.
Aristotle thinks sleep to be produced by a vapor generated by the heat energy in food, the fumes of which, rising to the brain, are there converted into moisture by the coldness of the brain itself, because, as he says, cold is felt at the contact just as rain is known to be made from vapor in contact with cold air; which moisture or humor, by force of gravity, is pushed downward, descends through the veins, drives the heat from the heart, and makes that cold also; whence, the cold spreading about, sleep, he says, generally arises.
This moisture, or humor,—ought to be warm, he writes; when it is cold, sleep will not be produced,—just as those affected with sleepiness show that their systems are in warm and at the same time humid condition; and children, who have abundance of this warm moisture, sleep the most; whence he states that this sleep chill has in fact its causes at the outset in this very warmth. These things he discusses partly in the book on “Sleep and Waking,” partly in the second of “The Parts of Animals,” and in “Problems.” I am not able to judge concerning the first matter, the idea of giving a single cause of sleep. For, according to this author, waking brings sleep;[12]since even animals, by means of waking and exercising their functions are known to become quiet and sleep, and it is said by him, that since animals become helpless in sleep, this helplessness is produced by the excess of waking that precedes it.
But not in waking, in food, or in this reason of generated vapor, is it possible to place the cause of sleep. Exercise produces this very effect. For through labor, deep and sweetest sleep falls upon the creatures; and this not on account of vapors rising from food, nor on account of a natural moisture, so much as by the violent exercise of the body. Foods that are cold or dried, as the hull of the mandrake,—taken into the body, induce sleep; which therefore is not accomplished because these foods give rise to vapors, since they would rather banish the vapors by their dryness; nor would these foods supply to the head what vapor is generated, since, repelled by the cold of such substances being taken into the body, the moisture would be repelled and chilled, and prevent the vapor from being carried to the brain. This would be so, as he says, only if the generation of vapors, and their ascent arose from the heating of this natural humor or moisture.
Other chapters of interest in Argenterio’s “Sleep and Waking” are:
Chapter II: What may bring sleep, and by what method, according to Galen.Chapter III: The causes producing sleep, which are thought true.Chapter XI: In what way sleep may be produced from natural heat.Chapter XIII: Concerning natural causes of Sleep and Waking.Chapter XIV: Concerning unnatural causes of Sleep and Waking.Chapter XVII: Of causes of long and short sleep.
Chapter II: What may bring sleep, and by what method, according to Galen.
Chapter III: The causes producing sleep, which are thought true.
Chapter XI: In what way sleep may be produced from natural heat.
Chapter XIII: Concerning natural causes of Sleep and Waking.
Chapter XIV: Concerning unnatural causes of Sleep and Waking.
Chapter XVII: Of causes of long and short sleep.