The Nature of Man: Studies in Optimistic Philosophy

It seems to be the case that the advance in the general organisation of animals has involved a less in the repro- ductive capacity of the cells and tissues. Even in the highest animals, some organs, such as the liver, still possess regenerative capacity ; but, on the other hand, many cells have lost the power of regeneration completely. The nervous cells, in particular, which are the highest and most perfectly organised elements of the body, cannot

embryonic develop- ment , they pass their lives without re- generating or repro- ducing. In acquiring ^kap^rf^ the highest quali- ties, that is to say, ^H their psychical acti- vity, they have lost completely the ^fe^- power of reproduc- tion, the distinctive FlG" '8--EPhemerids. feature of immortal cells. If cells doomed to natural death really exist, it is in the nervous tissues that we must look for them. The existence of natural death in the animal world cannot be denied, but it is very rare. The b^st example is that of the curious insects known universally as ephemerids (Fig. 18). Swarms of these delicate and graceful insects are to be seen in the summer months round lights. The perfect insects emerge from water, in which the six-legged larvae feed on the organic debris contained in fresh water. The larvae are not predaceous, and escape

from their numerous and hungry foes by agility. They are long-lived, some of them passing two or three years in the mud of streams, and in the end become winged insects after a rapid metamorphosis. Near Paris, anglers have a popular name (manne, manna) for one species (Palingenia virgo) which emerges in swarms after sundown from the waters of the Seine and Marne. The swarms fly in huge numbers, like heavy snow-flakes, for a very short time, and then fall into the water (Fig. 19). The flight of these insects lasts only an hour or two, and then, in an enfeebled condition, they fall down in vast numbers. They are attracted by the lanterns lighted by fishermen, and are collected to be used as bait. The life in the winged condition is truly ephemeral and lasts no more than a few hours. The structure of the insect is adapted to this short life. The larvae have powerful jaws, used in the mastication of food ; the winged insects possess only vestiges of jaws. They are unable to feed, and so are adapted only for the briefest existence. Their hour of aerial life is devoted to love. As soon as they emerge the males and females unite, and the packets of eggs, which are deposited at once, fall into the water, and in a few weeks the young larvae hatch out.

The mode of life and the organisation of the adult ephemerids show plainly that they are adapted to natural death. Death comes to them not because they are without food, or beause the environment fails to provide something necessary to life, but merely because they emerge from the larval state in a non-viable condition, without the organs necessary to the maintenance of life. Once it is granted that natural death actually exists, it is necessary to study its mechanism as closely as the existing state of knowledge permits. To exclude the

possibility of the death having to be interpreted as violent, it would be necessary to know that some very rapid infectious disease does not attack these insects as soon as they emerge from the water. This possibility, although remote, must be examined. Instances are known of large numbers of insects dying very rapidly as the result of attack by a species of mould which causes an epidemic. Every one has seen, especially in autumn, dead flies anchored to the window pane by a little tuft of white fluff. As so many individuals die about the same time, we might be disposed to assign the fact to natural death. The actual cause, however, is an infectious and fatal disease caused by a para- sitic mould.

The occurrence of some terrible epidemic may be excluded from consideration in the case of ephemcrids. I have made investigations which show that such an epidemic does not occur. The bodies of the dying ephe- merids contain no microbe which could be the cause of death. Their death must be regarded as natural, as the result of their organisation, as essentially a part of the nature of the insects. Among the cells of their body there are many active phagocytes. Is it possible to attribute death to ravages that these cells may cause among the higher cells and tissues ? Microscopic examination, so far from supporting such a possibility, shows that the organs are quite normal in their intimate structure. The brain and central nervous system, the muscles and other organs, show no signs of that invasion by phagocytes found in cases of senile degeneration. In this example of natural death there is certainly no possibility of phagocytic inter- vention

Some biologists have suggested that the rapid death of ephemerids and of some other insects is due to debility caused by the great effort of depositing the male and female sexual cells. On this 'supposition, the case would be analogous to the shock which is sometimes the consequence of a surgical operation. This hypothesis, however, may be excluded, for among the dead ephemerids there are many males that have not united with females. Among ephemerids males are much more numerous than females ; many males have no opportunity of undergoing the sexual shock and of emptying the reproductive organs, and these, none the less, die as rapidly as the others.

As yet we do not know if all the tissues of the ephemerids die simultaneously in natural death. Most probably the cells of the nervous centres perish first, and so bring death on the others. The investigation ought to be made. Death comes to the ephemerids in the midst of love, at the moment when their sexual instincts are satisfied. It would be very interesting to know the sensations of these creatures as they feel death come on them in the act of reproduction. Naturally it would be impossible to obtain a full answer to the question, but many interesting facts regarding it may be ascertained. All the ephemerids, not only those the life of which is so brief, but those that live for several days (Chloe, for instance), are extremely easy to cap- ture. It is unnecessary to take them unawares or to use a net as in the case of flies, wasps, and many other insects. Ephemerids may be taken with the fingers in the simplest way, because they offer no resistance and show no desire to escape, although they have six legs and two or four wings. This is not an isolated case, for some other insects (as, for example, winged ants and aphides) allow themselves to be captured with the same carelessness.

Although the adult ephemerids are careless, the wingless larvae are timid. When a tube is brought near them, among the water plants, with the object of capturing them, they rapidly move off. It often requires much patience and quickness to capture these larvae (Fig. 20). The instinct of preservation of life displays itself by rapid flight. It is remarkable that the adult insect has lost the instinct of self-preservation. If it be touched it may move a short distance off, but it does not take to flight although its wings are very large, and its body, which of itself weighs little, is still lighter because the digestive tube is filled with air and not with food. As a rule, an ephemerid that has been touched does not even move off, but

an ephemend allows itself to be captured without any resist - (Chioerufuium). ance. It would not be accurate to say that the larva's instinct of self-preservation has been replaced in the adult by an instinct for death ; but it must be admitted that the instinct of preservation has been totally lost. The lack of resistance cannot be explained by any defect in the organs of sense. Not only are the eyes of the larval stage fully preserved in the adult, but the adult males have enormous eyes to enable them to recognise the female in the turbulent flight which takes place at the close of the day. Ephemerids of all ages possess well developed tactile organs, and it is thus in spite of a highly organised sensory system that the adults offer no resistance to enemies.

It is no mere accident that the most striking examples of natural death occur among insects, for these creatures display an unusual stability in their cellular structure with a corresponding lack of the power of regeneration, in these particulars resembling man and the higher animals. The cells of the nervous system are very complex, and are well adapted for the highest function, that is to say, the psychical function. These highly endowed cells, however, are devoid

of the power of reproduction. Many experiments have been made in relation to this, and it has been proved clearly that in cold-blooded vertebrates the brain and spinal cord with the nerve cells contained in them are capable of regeneration, whilst among mammals only extremely rare cases are known in which there has been any regeneration of the nervous elements. It is to be expected, then, that cases of natural death occur in the higher animals and especially in man. However, no case is known so plain as that presented by the ephemerids. I have already stated that of deaths apparently due to senile debility in man, a large proportion are certainly due to various infectious diseases that affect the old, such as pneumonia and nephritis. Close examina- tion of the tissues confirms this conclusion, for the destruction of the higher elements by phagocytes produces what is really violent death and not a natural death like that of the ephemerids.

Natural death in man is probably a possibility rather than an actual occurrence. Old age is not a true physiological process but exhibits many morbid characters. That being the case, it is not surprising that it seldom ends in natural death. It is probable, however, that natural death occa- sionally occurs in very old men. Attempts have been made to estimate the natural limits of human life. Flourens * based a calculation on the duration of the period of growth. If the latter be taken as one fifth the natural life, then human life ought to last a century. As centenarians are rare, the vast majority of deaths, which happen before that age has been reached, must be regarded as violent or accidental. The rule of Flourens, however, is arbitrary, and there is no evidence to show that it is exact. Probably in the human race, as * "De la longevite humaine," Second Edition. Paris 1885.

in the case of ephemerids, the natural duration of life varies and cannot be expressed by a definite figure. In most cases it ought to be more than a hundred years, and only in rare cases ought it to be much less than that term. Probably there is a variation in the duration of life just as there is a variation of the date of sexual maturity for which rules may be laid down but not without anticipating numerous exceptions. The existing pathological character of old age vitiates all conclusions as to natural death, and it is still impossible to be exact in speaking of that subject. It is known that certain organs and tissues remain alive for some time after death. In the case of certain infectious diseases, the heart may be removed from a human body more than thirty hours after death, and if placed under proper conditions will renew its life, and beat for several hours. The white cor- puscles, the spermatozoa and the cilia of a corpse, may retain their power of movement. Does this also happen in the rare cases of natural death ? That question must be answered in the future. The most important question relating to natural death is the following : Is the appearance of natural death in man accompanied by the disappearance of one instinct, the instinct of self preservation, and by the appear- ance of another instinct, the instinct of death ? Do the phenomena of the ephemerids give us any indication as to this ? An exact answer is not to be expected. As old age is generally what may be called an unnatural phenomenon, it is extremely rare for persons to approach the age of natural death with their faculties unclouded. I have had under observation a centenarian old woman, who still re- membered some incidents of her youth ; in her the desire to live was still strong, but her intellectual faculties were partially dim. Moreover, her brain, of which I have already

spoken (p. 241), showed a marked degeneration of the nerve cells due to the activity of macrophags. I have obtained much information about a centenarian who was alive in Rouen in 1900, but a single glance at her photograph was enough to show that she no longer was in full possession of intelligence.* She was infirm in many ways. So also, Chevreul, the celebrated chemist, who died at the age of one hundred and three years, showed not the faintest wish for death ; he clung to life, but his mental powers had grown weak.

The cases to which I have referred are typical, but there are exceptions worthy of close attention. Tokarski, in the essay on the fear of death, to which I referred in the sixth chapter, quoted the case of a female centenarian who stated as follows : " If you come to live as long as I have lived, you will understand not only that it is possible not to fear death, but to feel the same need for death as for sleep." A new feeling had come into existence in the very old person, a feeling incomprehensible to those less old. Apparently this was a case in which the instinct of natural death had appeared in a centenarian whose mental faculties had been retained in a sufficiently perfect state.

I wish very much that I had myself been a witness of this old woman's remarkable instinct in even one case ol the many that I have observed. But all that have been pointed out to me as subject to this new desire have turned out to have been possessed of very different ideas. Some were old invalids, weary of pain and ready to exchange the sorrows of life for death, but who would have preferred to be healed and to live on in comfort. When the possibility of recover- ing health was suggested to them, they showed signs of pleasure and of the renewal of hope. * Journalde Rouen, September 2 3,1900. Article by Georges Dubosr

Investigations that I have made in homes for the aged have led to negative results on this subject. No case showed the slightest sign of the approach of the instinct of death. However, I have learned from Dr. Fauvel of one case to add to the instance noticed by Tokarski. It was the case of an old lady whose health and circumstances were comfortable and who before her death showed a real desire for it and stated it in much the same language as that quoted by Tokarski. In Fauvel's case, however, the old lady had reached the age of only eighty-five years. It seems probable that this was a second genuine case of the appearance of the instinct of death, and it is therefore interesting to notice that that instinct, like the sexual instinct, is subject to variation in the date of its appearance.

In my search for instances of the instinct of death, I made use of the large collection made by Lejoncourt,* but found that the information given by this author was very incomplete as to the mode of life and the last moments of his cases. The Bible testifies to the frequency of old age in ancient times and to the complete preservation of the faculties in the aged. It also contains some references that may be interpreted as instances of the instinct, of death. I may take its account of the death of some of the patriarchs. " And these are the days of the years of Abraham's life which he lived, an hundred threescore and fifteen years. Then Abraham gave up the ghost, and died in a good old age, an old man, and full of years. "f " And the days of Isaac were an hundred and fourscore years. And Isaac gave up the ghost, and died, and was gathered unto his people, being old and full of days: and his sons Esau and Jacob buried him." \ " After this lived Job an hundred and forty

years, and saw his sons, and his sons' sons, even four generations. So Job died, being old and full of days."* It is probable that the phrase "old and full of dajs," which sounds strange in our ears, simply refers to the instinct of death, developed in well-preserved old men who had attained ages of from 140 to 180 years, f The Biblical phrase is not merely a commonplace phrase applied to the death of cele- brities for the references to deaths of other persons were put in different language. " And these are the years of the life of Ishmael, an hundred arid thirty and seven years : and he gave up the ghost and died ; and was gathered unto his people."| " ^d Jacob lived in the land of Egypt seventeen years : so the whole age of Jacob was an hundred forty and seven years. "§ "And Aaron was an hundred and twenty and three years old when he died in Mount Hor." || " And Moses was an hundred and twenty years old when he died ; his eye was not dim, nor his natural force abated. "1 In only one of these later cases had the individual reached the age of one hundred and forty years, at which age, apparently, the instinct of natural death appeared.

It may seem altogether surprising and improbable to us that an instinct for death should arise in man, since we are imbued with an instinct of an opposite nature. From the facts that I collected in my sixth chapter, it was to be inferred plainly that the desire of life and the fear of death are manifestations of an instinct deep-rooted in the con- f It may bs that the great longevity of many of the patriarchs, ending in the appearance of the instinct of death, is the cause of the small extent to which the idea of a future life had been developed amongst the ancient Hebrews, (See chap, vii.)

stitution of man. That instinct is of the same order as the instincts of hunger and thirst, of the need of sleep, of move- ment and of sexual and maternal love. The devotion and care bestowed on their young by female birds and mammals are known universally. And yet these instincts can be reversed. There is no sacrifice of which the mothers are not capable if it serve to save the life or promote the well- being of their offspring. Such devotion is a manifestation of the maternal instinct, which is one of the strongest instincts known to us. And yet that love, so tender and so absolute, lasts only for the time during which the wants of the young need to be satisfied. As soon as the young begin to be independent, the maternal love changes to indifference or to dislike. At the next breeding-period, maternal love reappears again, so that there is a periodic ebb and flow of the instinct.

The new-born babe takes ah instinctive delight in the milk of his mother, which seems to him the only good food in the world. As soon as he can show his feelings, his intense satisfaction as he is suckled is plain. But this instinct lasts only during the period of lactation. As soon as the child begins to take different kinds of food, he ceases to be pleased with his mother's milk, and may dislike it for the remainder of his life. Several adults to whom I have offered human milk would not even taste it, so disgusting did it seem to them. And yet the taste had nothing in- trinsically disagreeable in it. Here again is an example of a strong instinct that changes completely.

Children often eat to repletion of some kind of substance, and for long afterwards that substance disgusts them instead of being coveted by them. It is said that apprentices to pastry-cooks and makers of sweetmeats are allowed at first to eat as much as they please. They soon come to have a profound dislike for the sweet things that children like so much. A mother who adores her child, or a child who is extremely fond of sweetmeats cannot understand how any mother could dislike her offspring or any apprentice have a distaste for sweets. In the same way, human beings full of the desire for life, believe more easily in eternal life than in the possibility of an instinct of death. And yet the instinct of death seems to lie, in some potential form, deep in the con- stitution of man. If the cycle of human life followed its ideal course according to physiological function, then the instinct of death would appear in its time, after a normal life and an old age healthy and prolonged.

In reality, human life is subject from its very beginning to the pernicious disharmonies in the constitution of man. This evil influence increases with the passing of the years and leads to an old age ruined by abnormalities. It is not surprising that under such circumstances men wish neither to grow old nor to die. Old men, in spite of their attach- ment to life, do not attain the capacity to know all that is good in it, and die, in the fear of death, without having known the instinct of death. They may be compared with unhappy women who have married before their sexual in- stincts have awakened and who have died in childbirth, without ever having known the real joy of loving. Formerly, the number of women in such a case was large. In some parts of Abyssinia, girls married when they were still very young and before their physical development was mature. According to Hassenstein,* nearly one third of these young women died in childbirth. They quitted life before they had known the true sexual instinct. The advancement of civilisation and of medical knowledge has greatly reduced * Ploss-Bartels, " Das Weib," vol. I. p. 620".

the number of such unhappy women. We must hope that the progress of knowledge will bring about a similar advance in relation to the instinct of death. With that progress, the number of men who will live until the instinct has been attained will become greater and greater. Disharmonies in the human constitution as the chief source of our sorrows — Scientific data as to the origin and destiny of man — The goal of human existence — Difficulties in the way of scientific investigation of the problem — What is progress ?— Difficulty of including the whole human race in a scheme of progress and morality — The instincts of life and of natural death — Application to real life of the doctrines set forth in hits book

MAN, who is a descendant of some anthropoid ape, has inherited a constitution adapted to an environment very different from that which now surrounds him. Man is possessed of a brain very much more highly developed than that of his ancestors, and has entered on a new path in the evolution of the higher organisms. The sudden change in his natural conditions has brought about a large series of organic disharmonies which become more and more acutely felt as he becomes more intelligent and more sensi- tive. And thus there has arisen a number of sorrows which poor humanity has tried to relieve by all the means in its power. The disharmonies in the sexual functions have brought into existence attempted remedies of the strangest kind. The greatest disharmony of the constitution is that of the morbid nature of old age and the impossibility of reaching the instinct of natural death ; this has produced childish and erroneous conceptions of the immortality of the soul and of the resurrection of the body, and many other

strange doctrines that have been imposed upon us as revealed truth. Human intelligence, in the course of its progressive evolu- tion, has rebelled against these naive palliatives. Finding the restoration of the much-desired harmony beyond its power, humanity became resigned to a passive fatalism, and believed even that the existence of man was a kind of bad joke, a faux pas in the evolution of sentient organisms. Exact science, developing slowly, but surely, has at last tried to master the situation. Moving step by step, passing from the simple to the complex and from the particular to the general, science has established a set of truths which all the world must accept.

Humanity in its misery has put question after question to science, and has lost patience at the slowness of the advance of knowledge. It has declared that the answers already found by science are futile and of little interest. From time to time it has preferred to turn back, and to delude itself with the beautiful mirages offered by religions and systems of philosophy. But science, confident of its methods, has quietly con- tinued to work. Little by little, the answers to some of the questions that have been set have begun to appear. Whence do we come ? science has been asked unceasingly. Is not man a being unlike other beings, made in the image of God, animated with the divine breath, and immortal ? No, science answers. Man is a kind of miscarriage of an ape, endowed with profound intelligence and capable of great progress. His brain is the seat of processes that are very complex, and much higher than those of other animals, but these functions are incompatible with the existence of an immortal soul.

things has absorbed the attention of man, and naturally so, for it is less important to know our origin than to know our destiny. Does death mean absolute extinction, or is it a gateway leading to a new and everlasting life ? And if the latter alternative be untrue, how are we to face in- evitable death ? Science cannot admit the immortality of the conscious soul, for consciousness is a function of special elements in the body that certainly cannot live for ever. Immortality exists only for very low organisms that renew their lives by repeated divisions with complete regeneration, and that have no highly developed consciousness.