An Essay on the Principle of Population

Chapter XII

Mr. Godwin’s conjecture concerning the indefinite prolongation of human life—Improper inference drawn from the effects of mental stimulants on the human frame, illustrated in various instances—Conjectures not founded on any indications in the past, not to be considered as philosophical conjectures—Mr. Godwin’s and Mr. Condorcet’s conjecture respecting the approach of man towards immortality on earth, a curious instance of the inconsistency of scepticism.

Mr. Godwin’s conjecture respecting the future approach of man towards immortality on earth, seems to be rather oddly placed in a chapter, which professes to remove the objection to his system of equality from the principle of population. Unless he supposes the passion between the sexes to decrease faster, than the duration of life increases, the earth would be more encumbered than ever. But leaving this difficulty to Mr. Godwin, let us examine a few of the appearances from which the probable immortality of man is inferred.

To prove the power of the mind over the body, Mr. Godwin observes, “How often do we find a piece of good news dissipating a distemper? How common is the remark that those accidents which are to the indolent a source of disease, are forgotten and extirpated in the busy and active? I walk twenty miles in an indolent and half determined temper, and am extremely fatigued. I walk twenty miles full of ardour, and with a motive that engrosses my soul, and I come in as fresh and as alert as when I began my journey. Emotion excited by some unexpected word, by a letter that is delivered to us, occasions the most extraordinary revolutions in our frame, accelerates the circulation, causes the heart to palpitate, the tongue to refuse its office, and has been known to occasion death by extreme anguish or extreme joy. There is nothing indeed of which the physician is more aware than of the power of the mind in assisting or reading convalescence.”

The instances here mentioned, are chiefly instances of the effects of mental stimulants on the bodily frame. No person has ever for a moment doubted the near, though mysterious connection, of mind and body. But it is arguing totally without knowledge of the nature of stimulants to suppose, either that they can be applied continually with equal strength, or if they could be so applied, for a time, that they would not exhaust and wear out the subject. In some of the cases here noticed, the strength of the stimulus depends upon its novelty and unexpectedness. Such a stimulus cannot, from its nature, be repeated often with the same effect, as it would by repetition lose that property which gives it its strength.

In the other cases, the argument is from a small and partial effect, to a great and general effect, which will in numberless instances be found to be a very fallacious mode of reasoning. The busy and active man may in some degree counteract, or what is perhaps nearer the truth, may disregard those slight disorders of frame which fix the attention of a man who has nothing else to think of; but this does not tend to prove that activity of mind will enable a man to disregard a high fever, the smallpox, or the plague.

The man who walks twenty miles with a motive that engrosses his soul, does not attend to his slight fatigue of body when he comes in; but double his motive, and set him to walk another twenty miles, quadruple it, and let him start a third time, and so on; and the length of his walk will ultimately depend upon muscle and not mind. Powel, for a motive of ten guineas, would have walked further probably than Mr. Godwin, for a motive of half a million. A motive of uncommon power acting upon a frame of moderate strength, would, perhaps, make the man kill himself by his exertions, but it would not make him walk a hundred miles in twenty-four hours. This statement of the case, shews the fallacy of supposing, that the person was really not at all tired in his first walk of twenty miles, because he did not appear to be so, or, perhaps, scarcely felt any fatigue himself. The mind cannot fix its attention strongly on more than one object at once. The twenty thousand pounds so engrossed his thoughts, that he did not attend to any slight soreness of foot, or stiffness of limb. But had he been really as fresh and as alert, as when he first set off, he would be able to go the second twenty miles with as much ease as the first, and so on, the third, &c. which leads to a palpable absurdity. When a horse of spirit is nearly half tired, by the stimulus of the spur, added to the proper management of the bit, he may be put so much upon his mettle, that he would appear to a stander-by, as fresh and as high spirited as if he had not gone a mile. Nay, probably, the horse himself, while in the heat and passion occasioned by this stimulus, would not feel any fatigue; but it would be strangely contrary to all reason and experience, to argue from such an appearance, that if the stimulus were continued, the horse would never be tired. The cry of a pack of hounds will make some horses, after a journey of forty miles on the road, appear as fresh, and as lively, as when they first set out. Were they then to be hunted, no perceptible abatement would at first be felt by their riders in their strength and spirits, but towards the end of a hard day, the previous fatigue would have its full weight and effect, and make them tire sooner. When I have taken a long walk with my gun, and met with no success, I have frequently returned home feeling a considerable degree of uncomfortableness from fatigue. Another day, perhaps, going over nearly the same extent of ground with a good deal of sport, I have come home fresh, and alert. The difference in the sensation of fatigue upon coming in, on the different days, may have been very striking, but on the following mornings I have found no such difference. I have not perceived that I was less stiff in my limbs, or less footsore, on the morning after the day of the sport, than on the other morning.

In all these cases, stimulants upon the mind seem to act rather by taking off the attention from the bodily fatigue, than by really and truly counteracting it. If the energy of my mind had really counteracted the fatigue of my body, why should I feel tired the next morning? If the stimulus of the hounds had as completely overcome the fatigue of the journey in reality, as it did in appearance, why should the horse be tired sooner than if he had not gone the forty miles? I happen to have a very bad fit of the tooth-ache at the time I am writing this. In the eagerness of composition, I every now and then, for a moment or two, forget it. Yet I cannot help thinking that the process, which causes the pain, is still going forwards, and that the nerves which carry the information of it to the brain, are even during these moments demanding attention, and room for their appropriate vibrations. The multiplicity of vibrations of another kind, may perhaps prevent their admission, or overcome them for a time when admitted, till a shoot of extraordinary energy puts all other vibration to the rout, destroys the vividness of my argumentative conceptions, and rides triumphant in the brain. In this case, as in the others, the mind seems to have little or no power in counteracting, or curing the disorder, but merely possesses a power, if strongly excited, of fixing its attention on other subjects.

I do not, however, mean to say that a sound and vigorous mind has no tendency whatever to keep the body in a similar state. So close and intimate is the union of mind and body that it would be highly extraordinary, if they did not mutually assist each other’s functions. But, perhaps, upon a comparison, the body has more effect upon the mind than the mind upon the body. The first object of the mind is to act as purveyor to the wants of the body. When these wants are completely satisfied, an active mind is indeed apt to wander further, to range over the fields of science, or sport in the regions of imagination, to fancy that it has “shuffled off this mortal coil,” and is seeking its kindred element. But all these efforts are like the vain exertions of the hare in the fable. The slowly moving tortoise, the body, never fails to overtake the mind, however widely and extensively it may have ranged, and the brightest and most energetic intellects, unwillingly as they may attend to the first or second summons, must ultimately yield the empire of the brain to the calls of hunger, or sink with the exhausted body in sleep.

It seems as if one might say with certainty, that if a medicine could be found to immortalize the body there would be no fear of its being accompanied by the immortality of the mind. But the immortality of the mind by no means seems to infer the immortality of the body. On the contrary, the greatest conceivable energy of mind would probably exhaust and destroy the strength of the body. A temperate vigour of mind appears to be favourable to health; but very great intellectual exertions tend rather, as has been often observed, to wear out the scabbard. Most of the instances which Mr. Godwin has brought to prove the power of the mind over the body, and the consequent probability of the immortality of man, are of this latter description, and could such stimulants be continually applied, instead of tending to immortalize, they would tend very rapidly to destroy the human frame.

The probable increase of the voluntary power of man over his animal frame, comes next under Mr. Godwin’s consideration, and he concludes by saying, that the voluntary power of some men, in this respect, is found to extend to various articles in which other men are impotent. But this is reasoning against an almost universal rule from a few exceptions: and these exceptions seem to be rather tricks, than powers that may be exerted to any good purpose. I have never heard of any man who could regulate his pulse in a fever; and doubt much, if any of the persons here alluded to, have made the smallest perceptible progress in the regular correction of the disorders of their frames and the consequent prolongation of their lives.

Mr. Godwin says, “Nothing can be more unphilosophical, than to conclude, that, because a certain species of power is beyond the train of our present observation, that it is beyond the limits of the human mind.” I own my ideas of philosophy are in this respect widely different from Mr. Godwin’s. The only distinction that I see, between a philosophical conjecture, and the assertions of the Prophet Mr. Brothers, is, that one is founded upon indications arising from the train of our present observations, and the other has no foundation at all. I expect that great discoveries are yet to take place in all the branches of human science, particularly in physics; but the moment we leave past experience as the foundation of our conjectures concerning the future; and still more, if our conjectures absolutely contradict past experience, we are thrown upon a wide field of uncertainty, and any one supposition is then just as good as another. If a person were to tell me that men would ultimately have eyes and hands behind them as well as before them, I should admit the usefulness of the addition, but should give as a reason for my disbelief of it, that I saw no indications whatever in the past from which I could infer the smallest probability of such a change. If this be not allowed a valid objection, all conjectures are alike, and all equally philosophical. I own it appears to me, that in the train of our present observations, there are no more genuine indications that man will become immortal upon earth, than that he will have four eyes and four hands, or that trees will grow horizontally instead of perpendicularly.

It will be said, perhaps, that many discoveries have already taken place in the world that were totally unforeseen and unexpected. This I grant to be true; but if a person had predicted these discoveries, without being guided by any analogies or indications from past facts, he would deserve the name of seer or prophet, but not of philosopher. The wonder that some of our modern discoveries would excite in the savage inhabitants of Europe in the times of Theseus and Achilles, proves but little. Persons almost entirely unacquainted with the powers of a machine cannot be expected to guess at its effects. I am far from saying, that we are at present by any means fully acquainted with the powers of the human mind; but we certainly know more of this instrument than was known four thousand years ago; and therefore, though not to be called competent judges, we are certainly much better able, than savages, to say what is, or is not, within its grasp. A watch would strike a Savage with as much surprize as a perpetual motion; yet one, is to us a most familiar piece of mechanism, and the other, has constantly eluded the efforts of the most acute intellects. In many instances, we are now able to perceive the causes, which prevent an unlimited improvement in those inventions, which seemed to promise fairly for it at first. The original improvers of telescopes would probably think, that as long as the size of the specula, and the length of the tubes could be increased, the powers and advantages of the instrument would increase; but experience has since taught us, that the smallness of the field, the deficiency of light, and the circumstance of the atmosphere being magnified, prevent the beneficial results that were to be expected from telescopes of extraordinary size and power. In many parts of knowledge, man has been almost constantly making some progress; in other parts, his efforts have been invariably baffled. The Savage would not probably be able to guess at the causes of this mighty difference. Our further experience has given us some little insight into these causes, and has therefore enabled us better to judge, if not, of what we are to expect in future, at least of what we are not to expect, which, though negative, is a very useful piece of information.

As the necessity of sleep seems rather to depend upon the body than the mind, it does not appear how the improvement of the mind can tend very greatly to supersede this “conspicuous infirmity.” A man who by great excitements on his mind is able to pass two or three nights without sleep, proportionably exhausts the vigour of his body: and this diminution of health and strength will soon disturb the operations of his understanding; so that by these great efforts he appears to have made no real progress whatever, in superseding the necessity of this species of rest.

There is certainly a sufficiently marked difference in the various characters of which we have some knowledge, relative to the energies of their minds, their benevolent pursuits, &c. to enable us to judge, whether the operations of intellect have any decided effect in prolonging the duration of human life. It is certain, that no decided effect of this kind has yet been observed. Though no attention of any kind has ever produced such an effect, as could be construed into the smallest semblance of an approach towards immortality; yet of the two, a certain attention to the body, seems to have more effect in this respect than an attention to the mind. The man who takes his temperate meals and his bodily exercise, with scrupulous regularity, will generally be found more healthy, than the man who, very deeply engaged in intellectual pursuits, often forgets for a time these bodily cravings. The citizen who has retired, and whose ideas, perhaps, scarcely soar above, or extend beyond his little garden, puddling all the morning about his borders of box, will, perhaps, live as long as the philosopher whose range of intellect is the most extensive, and whose views are the clearest of any of his contemporaries. It has been positively observed by those who have attended to the bills of mortality, that women live longer upon an average than men; and, though I would not by any means say that their intellectual faculties are inferior, yet, I think, it must be allowed, that from their different education, there are not so many women as men, who are excited to vigorous mental exertion.

As in these and similar instances, or to take a larger range, as in the great diversity of characters that have existed during some thousand years, no decided difference has been observed in the duration of human life from the operation of intellect, the mortality of man on earth seems to be as completely established, and exactly upon the same grounds, as any one, the most constant, of the laws of nature. An immediate act of power in the Creator of the Universe might, indeed, change one or all of these laws, either suddenly or gradually; but without some indications of such a change, and such indications do not exist, it is just as unphilosophical to suppose that the life of man may be prolonged beyond any assignable limits, as to suppose that the attraction of the earth will gradually be changed into repulsion, and that stones will ultimately rise instead of fall, or that the earth will fly off at a certain period to some more genial and warmer sun.

The conclusion of this chapter presents us, undoubtedly, with a very beautiful and desirable picture, but like some of the landscapes, drawn from fancy and not imagined with truth, it fails of that interest in the heart which nature and probability can alone give.

I cannot quit this subject without taking notice of these conjectures of Mr. Godwin and Mr. Condorcet, concerning the indefinite prolongation of human life, as a very curious instance of the longing of the soul after immortality. Both these gentlemen have rejected the light of revelation which absolutely promises eternal life in another state. They have also rejected the light of natural religion, which to the ablest intellects in all ages, has indicated the future existence of the soul. Yet so congenial is the idea of immortality to the mind of man, that they cannot consent entirely to throw it out of their systems. After all their fastidious scepticisms concerning the only probable mode of immortality, they introduce a species of immortality of their own, not only completely contradictory to every law of philosophical probability, but in itself in the highest degree narrow, partial, and unjust. They suppose that all the great, virtuous, and exalted minds, that have ever existed, or that may exist for some thousands, perhaps millions of years, will be sunk in annihilation; and that only a few beings, not greater in number than can exist at once upon the earth, will be ultimately crowned with immortality. Had such a tenet been advanced as a tenet of revelation, I am very sure that all the enemies of religion, and probably Mr. Godwin and Mr. Condorcet among the rest, would have exhausted the whole force of their ridicule upon it, as the most puerile, the most absurd, the poorest, the most pitiful, the most iniquitously unjust, and, consequently, the most unworthy of the Deity that the superstitious folly of man could invent.