PART IX

SCIENCE AND MORALITY

I

UTILITARIAN AND INTUITIVE MORALITY

Difficulty of the problem of morality—Vivisection and anti-vivisection—Enquiry into the possibility of rational morality—Utilitarian and intuitive theories of morality—Insufficiency of these

In the course of this book I have from time to time approached subjects closely related with the problem of morality. For instance, in considering the prolongation of human life, it was necessary to show that extension of longevity far beyond the reproductive period of man in no way is opposed to the principles of the highest morality, although there exist races who find the sacrifice of old people in harmony with their conception of morality.

Experimental biology, which lies at the root of most of the doctrines exposed in this work, depends on vivisection of animals. There are, however, very many persons who regard it as immoral to operate on living animals when it is not for the direct benefit of these. The attempts which have been made in France and Germany to prevent or to limit vivisection in laboratories have not succeeded, but in England there is a severe law controlling operations on animals and submitting them to oppressive regulations to which many of the scientific men in the country are opposed.

The question of experiments upon human beings is still more delicate. Just as formerly the examination of a human corpse could be made only in secret, so at the present time, if the slightest experiment is to be made upon a human being, it can be only by devious ways. People who are hardly shocked at all at the numberless accidents caused by automobiles and other means of transit, or in field sports, make the strongest protest against any proposal to try some new method of treatment upon a human being.

A large number of people, amongst them even men of science, regard as immoral any attempt to prevent the spread of venereal diseases. Recently, in connection with the investigations into the action of mercurial ointment as a means of preventing syphilis, the members of the Faculty of Medicine in France made a public protest, declaring that it would be “immoral to let people think that they could indulge in sexual vice without danger,” and that it was “wrong to give to the public a means of protection in debauch.”[226] None the less, other men of science, equally serious, were convinced that they were performing an absolutely moral work in attempting to find a prophylactic against syphilis which would preserve many people, including children and other innocent persons who, if no preventive measures existed, would suffer from the terrible disease.

Such examples show the reader what confusion exists in the problem of morality. Although at every moment, in every act of human conduct, the precepts of morality must be reckoned with, even the most authoritative persons are far from agreeing as to what rules to follow. About a year ago in a Parisian journal[227] an enquiry into the subject of rational morality was directed to distinguished authors. The object was to discover if, at the present time, moral conduct could be based not on religious dogma, which binds only those who believe in it, but on rational principles. The answers were most contradictory. Some denied the possibility of rational morality, others admitted it, but in very different fashions. Whilst one philosopher, M. Boutroux, held that “morality must be founded on reason and could have no other foundation,” a poet, M. Sully-Prudhomme, turned to feeling and conscience as the basis of morality. According to him, “in the teaching of morality, it is the heart and not the mind which is at once master and pupil.” In the contradictions which I mentioned in the beginning of this chapter, these two views appear. When antivivisectionists are protesting against experiments on animals, they are inspired by sympathy for poor creatures which cannot defend themselves. Guided by conscience, they think immoral any suffering inflicted upon a living being for the benefit of another being, whether human or animal. I know distinguished physiologists who have determined to limit their experiments to animals with little sensibility, such as frogs. The great majority of scientific men, however, would have no scruple in opening bodies and subjecting their victims to severe suffering in the hope of clearing up some scientific problem which sooner or later would increase the happiness of human beings and animals. If vivisection had not been performed, or if it had been restricted, the great laws of infectious diseases would not have been discovered, nor would the discovery of many valuable remedies have been made. To justify investigation, men of science set out from the utilitarian theory of morality, which approves everything that is useful to the human race. The antivivisectionists, on the other hand, rely on the intuitive theory, according to which conduct is controlled by the spontaneous activity of our conscience.

In the case which I have selected the problem is easy to solve. It is plain that vivisection is inevitable in the experimental investigation of vital processes, as it is the only means by which serious progress can be made. None the less, very many people cannot accept this necessity, because of the intensity of their love for animals.

In the question of the prevention of syphilis, the moral problem is still more easy to settle. Whilst in the case of vivisection a real suffering may be inflicted upon animals, in preventive measures against syphilis, the evil is more or less intricate and very problematic. The certainty of safety from this disease might render extra-conjugal relations more frequent, but if we compare the evil which might come from that with the immense benefit gained in preventing so many innocent persons from becoming diseased, it is easy to see to which side the scale dips. The indignation of those who protest against the discovery of preventive measures can never either arrest the zeal of the investigators or hinder the use of the measures. This example again shows that reasoning is necessary in the solution of most moral questions.

However, the problems which arise in actual life are often very much more complicated than the two cases I have taken as an introduction. It is easy to prove the high utility of the work of vivisectors and of those who are seeking means of preventing syphilis, whilst their adversaries have nothing to invoke but their feelings. The situation is quite different in many questions which border on morality. The sexual life abounds in extremely difficult problems, in which it is almost impossible to determine what is right. Let me recall the vagaries in the life of Goethe, whose great genius was so often in conflict with the morality of his time. Was he wrong in giving up Frederique and Lili from the fear that a permanent bond would damage his poetic productivity? Then there is the moral question of the marriage of men affected with syphilis, or other diseases which might influence the offspring. The problems of the continence of young people before marriage, of prostitution and of means of preventing conception are without doubt questions of great importance, the solution of which is extremely difficult from the point of view of morality. Differences of opinion are revealed in nearly everything relating to punishment. The question of the death penalty is much in dispute and requires numerous investigations of different kinds. Statistics have been collected to give information as to the utility or inutility of the death penalty. According to some results, capital punishment does not diminish the number of crimes, whilst according to others it has a real preventive effect. Punishments less violent than death, and particularly the punishments of children, are equally troublesome, and schoolmasters have difficulty in finding a solution.

The utilitarian theory of morality often finds it impossible to prove the advantage of the conduct it prescribes, and this the more because in many cases we do not exactly know who is to profit by it. Is the utility of any particular act to be considered so far as it affects relatives, members of the same religion, of the same country, or of the same race, or all humanity?

In face of these difficulties, many moral philosophers have given up the utilitarian theory and declared for an intuitive theory. The basis of morality is to be found in a feeling innate in every man, a sort of social instinct urging him to do good to his neighbour, and which, by the voice of his own conscience, dictates how he ought to act much more precisely than could be done by any comprehension of the utility of his conduct.

It is certainly true that man is an animal living in society because of his need for association with other human beings. But whilst in the animal world the members of societies are actuated by an instinct which is blind and generally very precise, in man we find nothing of the kind. The social instinct appears in him in endless variety. In some of us love of neighbours is extremely highly developed, so that some persons are only happy when sacrificing themselves for the public good. They give all that they have to the poor, and often die for some ideal which is necessarily altruistic. Such examples are rare. Many men, however, profess an affection for some of their kind, devote themselves to their relations, their friends, or their compatriots, and remain practically indifferent to all others. Other individuals, again, have an even narrower sphere of affection, and take advantage of their fellows, either in their own interest or in that of their own family. Still more rare are the really wicked persons who have no love for anyone but themselves and who take pleasure in doing harm to those about them. Notwithstanding this diversity in the development of the social instinct, all men have to live together.

If it were possible to know the inner motives of men, these might be used as a basis for classifying conduct. Those acts might be described as moral which were inspired by neighbourly love, and those as immoral the motive of which was egoism. But it is seldom that the real motives are discovered; they lie deep down in the individual mind, sometimes unknown even to the man himself. We can nearly always harmonise our acts with the dictates of our consciences and find reasons for the harm we inflict upon others. It is only rare natures that possess a conscience so delicate as to be always tormented lest they are not doing good to their neighbours.

In the course of life, men are disposed to attribute bad motives to their opponents. Such an attitude makes criticism easier and panders to the common wish to speak evil of one’s neighbours. Notwithstanding the numerous precedents for such an attitude amongst politicians and journalists, it must be discarded from any serious study of morality.

The motives and the conscience are elusive elements of little use in any attempt to value human conduct. We have to fall back on the consequences of action. Now it is easy to show that the social instinct often leads to action which is not good. It frequently happens that men, acting with the highest and best intentions, do much harm. Schopenhauer long ago pointed out that morality based on sentiment is a mere caricature of real morality. Impelled by the altruistic wish to do good, men often lavish unreflecting charity and do harm to others and to themselves. In _Timon of Athens_ Shakespeare depicted

A most incomparable man; breathed, as it were, To an untirable and continuate goodness,

and who gave away to the right and the left, creating around him a cloud of parasites. He finally ruined himself and became a hopeless misanthrope. Shakespeare put his verdict in the mouth of Flavius:—

Undone by goodness. Strange, unusual blood, When man’s worst sin is, he does too much good.

Morality, founded purely on sentiment, has inspired the attacks on vivisectors which in all confidence spread evil amongst men.

It is a surprising result of the great complexity of human affairs, that society is sometimes better served by wicked acts than by acts inspired by the most generous feelings. Thus extremely rigorous measures of repression are often more successful than the half-measures employed by humane and charitable administrators.

The intuitive theory of morality has had no greater success than utilitarianism. Even if the sentiment of society were a true basis of moral conduct, it fails in actual practice. On the other hand, although utility is the object of all morality, it is in most cases so difficult to determine what is really useful, that utilitarianism breaks down as the foundation of morality.

We must look elsewhere for principles which can guide us towards right conduct.

II

MORALITY AND HUMAN NATURE

Attempts to found morality on the laws of human nature—Kant’s theory of moral obligation—Some criticisms of the Kantian theory—Moral conduct must be guided by reason

Even in antiquity, there were efforts to find a basis for morality other than the precepts of religion based on revelation, but the failure of such attempts has long been admitted. In the first chapter of _The Nature of Man_, I described such efforts to find a basis for morality in human nature itself. The Epicureans and the Stoics, although their doctrines were opposed, each claimed to set out from human nature. The principle is too vague for practical use, as human nature can be interpreted in very different fashions.

When several attempts to find a rational basis for morality had failed, Kant’s theory appeared and was hailed by many as a real advance. None the less, it has not met with general approval and may be taken as a supreme instance of the failure to solve the great problem of morality by reason. I do not wish to deal with it at length, but a review of its main outlines is pertinent to my argument.

According to Kant, morality cannot be founded on the feeling of sympathy, nor can it have as its object the happiness of men. Nature would have been an unskilful workman were her object the happiness of human beings, for many lower animals have much more happiness. An inner law is the force compelling us to morality, and without that we should have to seek our guide in happiness.

Kant’s doctrine is an intuitive theory of morality. It is based neither on sympathy nor on any inherent charity, which would make us covet happiness for our fellows, but solely on the consciousness of duty. Kant thought that the action of a man who wished to do good to his fellows was devoid of merit. Conduct was moral only in so far as it was obedience to the inner sense of duty. Schiller’s epigram has thrown into relief this part of the great philosopher’s theory, “When I take pleasure in doing good to my neighbour, I am uneasy, as I fear that I have been lacking in virtue.”

In his criticism of Kant’s system, Herbert Spencer drew a picture of a world inhabited by men who had no sympathy for their fellows and who did good to them against their natural instincts and only from a pure sense of duty. Spencer thought that such a world would be uninhabitable. Clearly, moral conduct, on the Kantian basis, could be followed only by exceptional persons, for most men follow their inclinations rather than any sense of duty. People of lower culture would accept kindnesses from others without caring whether the motive were kindness or a sense of duty, but highly civilised people would not endure service from those whom they knew to be acting against their instincts in obedience to a sense of duty. And so men would be driven to hide the real motives of their conduct, lest they should offend the sensibility of those towards whom their moral conduct was directed. Such cases, where the real motive is concealed, show how impossible it is to judge of conduct from the motives which may be supposed to have inspired it. As it is generally impossible to know whether some altruistic conduct has been inspired by kindness or has been performed as a duty, it is better to give up any attempt to appraise the springs of moral conduct.

Kant himself realised the need of some other standard for appraising human conduct. With such a purpose he arrived at his well-known maxim:—“Let your conduct be such that your motive might serve as a standard of universal application.” To explain the maxim he gave a number of examples. A man who is without money and cannot pay a debt is in doubt as to whether he should promise to repay his creditor. According to Kant, he ought to ask himself what would be the result if such a promise were to be made under similar circumstances by everyone. It is plain that if such false promises became universal, they would cease to be believed and so would be impracticable in actual life. Kant’s formula, therefore, would supply a rational basis for the discrimination of immoral conduct. In the case of theft it would operate as follows: if it became the custom for everyone to take whatever he wanted, private property and theft would simultaneously cease to exist. So also suicide is immoral, since if it became general the human race would cease to exist.

Kant, however, was looking at only one side of the problem. Moral conduct is frequently limited to an individual, and cannot be generalised for all humanity. Thus, for instance, if one about to sacrifice his life for the good of his fellows were to estimate his action according to Kant’s formula, he would reach a conclusion similar to that in the case of suicide; if everyone were to sacrifice his life for others, no one would remain alive, and so, according to Kant, the sacrifice of one’s life for the good of others would be an immoral act.

It is plain that in his search for a rational basis of morality, Kant found only a hollow form, void of any substantial body of morality. It is not enough that a moral man should take his consciousness of duty as a guide. He must know what would be the result of his acts. If it is immoral to make a false promise, it is because people would lose confidence in such promises, and confidence is necessary to our well-being. When the formula of Kant condemns theft, it is because, if theft became general, there could be no private property, and property is regarded as necessary to the well-being of men. Suicide is immoral, according to Kant, because it would lead to the disappearance of the human race, and human life is of course a good.

Kant tried to found his theory of morality on a rational basis which excluded the idea of the general good, but it was impossible for him to avoid it. His “practical reason,” when it raised the consciousness of duty to a principle, should have pointed the goal towards which moral acts were to be directed. In this matter, I find that Kant’s ideas are very vague, although extremely interesting.

The innate feeling of duty implies the _will_ to pursue moral conduct. This will is independent of the circum-ambient conditions. Kant in his nebulous language explains this consideration as follows:—“Our reason informs us of a law to which all our maxims are subject, as if our will had created its own natural order of things. This law, then, is in the sphere of a nature which we do not know empirically but which the freedom of the will makes possible, a nature which is supra-sensible, but which from the practical point of view we make objective, because it is created by our will in virtue of our existence as rational beings. The difference between the laws of a nature to which the will is subject and a nature subject to the will subsists in this, that in the first the objects must be the causes which determine the will, whilst in the second, the will itself causes the objects so that the causality of the will resides exclusively in pure reason, pure reason being thus practical reason” (_Critique of Practical Reason_).

So far as I can follow the argument of Kant, it seems to me to imply that rational morality cannot be bound by human nature as it exists. I may perhaps interpret Kant’s thought as if he had the intuition that the moral will was capable of modifying nature by subjecting it to its own laws.

On the other hand, several critics of Kant have attempted to improve his theory of morality by reconciling it with human nature as it actually exists. Vacherot,[228] for instance, has taken such an attitude in the most definite fashion. He insists that Kant “did not appreciate the capital importance of the object of the moral law. The problem which under the designation _summum bonum_ absorbed the schools of antiquity plays a minor part in the Kantian theory. Kant should have recognised that human destiny is not limited to duty but must include happiness” (p. 316).

But what is this “happiness” which is to be the standard of human actions? To answer this Vacherot places himself in the position of those ancient philosophers whom I discussed in _The Nature of Man_. He makes his point absolutely clear. “What is the ‘good’ for any being? The attaining of its purpose. What is the purpose of a being? The simple development of its nature. Apply this to man and morality. When human nature is known by observation and analysis, the deduction can be made as to what is the purpose, and the good, and therefore the law of man. For the conception of the good necessarily involves the idea of duty and of law to be imposed on the will. We have to fall back, then, on knowledge of man, but it must be complete knowledge, a recognition of the faculties, feelings, and inclinations that are peculiar to him and that distinguish him from animals” (p. 319). Here is a summary of this doctrine:—“Develop all our natural powers, subordinating those which are subsidiary to those which form the peculiar quality of human beings; this is the true economy of the little world we call human life; this is its purpose and this its law. The formula states in the most scientific and least doubtful form a very old truth, the foundation of all morality and the test of all its applications. If we seek to know what are justice, duty and virtue, we must look in the world itself, and not above or below it” (Op. 301).

Professor Paulsen, a more recent critic of Kant, comes to a similar conclusion.[229] He thinks that Kant should have modified his formula in some such way as follows:—“The laws of morality are rules which might serve for a natural legislation for human life; in other words, rules that, when they guided conduct according to natural law, would result in the preservation and supreme development of human life.”

From whatever side we examine the problem of morality, we come to submit conduct to the laws of human nature. Sutherland, a modern author who discusses morality by the scientific method, defines morality as “conduct guided by rational sympathy.” Such sympathy would not subordinate the chief good of others to an advantage less important but more immediate. Thus a mother may sympathise with her child when it has to take some unpleasant medicine; but if her sympathy be rational she will not let it interfere with the health of the child.

In the foregoing case, sympathy has to be controlled by medical knowledge. In moral conduct generally, reason must be the determining factor, whatever be the inspiring motive of the conduct, whether it come from sympathy or from the sense of duty. And thus morality in the last resort must be based on scientific knowledge.

III

INDIVIDUALISM

Individual morality—History of two brothers brought up in same circumstances, but whose conduct was quite different—Late development of the sense of life—Evolution of sympathy—The sphere of egoism in moral conduct—Christian morality—Morality of Herbert Spencer—Danger of exalted altruism

Although moral conduct refers specially to the relations between men, there exists a morality of the individual. As this latter is simpler, I shall consider it first in my investigation of rational morality.

When a man, seeking his individual happiness, gives way to his inclinations without restraint, he often comes to behave in a way that is generally regarded as immoral. Following his inclination, he may become idle and drunken. Idleness may depend on some irregularity of the brain, and may thus be as natural as is the wish to take drink in the case of a man to whom alcohol brings a feeling of well-being and gaiety. Why is it that idleness and alcoholism are immoral? Is it because they prevent the living of life in its completest and widest sense, according to the theory of Herbert Spencer? But it is precisely in this way that the adherents of the theory justify all kinds of excess without which fullness and width of life seem to them impossible.

Whilst vices such as idleness and drunkenness arise directly from qualities of the human constitution, they must be regarded as immoral because they prevent the completion of the ideal cycle of human life. I knew two brothers, almost the same age, subject to the same influences, and brought up in the same environment. None the less, their tastes and conduct were very different. The older brother, although very intelligent, during his college career devoted himself eagerly to bodily exercises and indulged in every way his inclination for pleasure. “As the chief end of life is happiness,” he said, “one must try to get as much of it as possible,” and so he got into the habit of visiting places where there was most amusement. Cards, good living, and women furnished for him the means of pleasure. As his ability was unusual, he passed his examinations almost without having worked. The example of his younger brother, always a devoted student, did not attract him. “It is all very well for you,” he said, “as you find your happiness in work; as for me, I detest books, and I am happy only when I am giving myself up to pleasure. Everyone must take his own road to the goal of life.” As a result, the health of the older brother was seriously affected by his mode of life. He acquired some disease of the circulatory system, had to face the end, and died at the age of fifty-six. The last years of his life were very unhappy, as the instinct of life developed in him extremely strongly. He was a victim of his own ignorance because when he was young he did not know that the sense of life would develop later on, and would become much stronger than in his youth. His brother was equally unaware of this fact, but, absorbed in scientific study, he kept himself apart from the indulgences of youth and lived a sober life. In this way he found that his strength and activity were fully preserved at a time of life when his older brother was already a physical wreck.

I have quoted this example, not to repeat the banal idea that a sober life is followed by a healthier old age than an intemperate life, but because I wish to insist on the importance of the development of the instinct of life in the course of each individual life. I see that this idea is very little known. I was present at the last moments of my older brother (he was called Ivan Ilyitch, and he was the subject of the famous story of Tolstoi: _The Death of Ivan Ilyitch_). Knowing that he was going to die from pyemia, at the age of forty-five, my brother preserved his great intelligence in all its clearness. As I sat by his bedside he told me his reflections in the most objective fashion possible. The idea of his death was for long very terrible to him, but “as we all die” he came to “resign himself, saying that after all there was only a quantitative difference between death at the age of forty-five and later on.” This reflection, which relieved the moral sufferings of my brother, is none the less untrue. The sense of life is very different at different ages, and a man who lives beyond the age of forty-five experiences many sensations which he did not know before. There is a great evolution of the mind during the advance of age.

Even if we do not accept the existence of an instinct of natural death as the crown of normal life, we cannot deny that youth is only a preparatory stage and that the mind does not acquire its final development until later on. This conception should be the fundamental principle of the science of life and the guide for education and practical philosophy.

Individual morality consists of conduct permitting the accomplishment of the normal cycle of life and ending in a feeling of satisfaction as complete as possible and which can be reached only in advanced age. And so, when we see a man wasting his health and strength and youth, and thus making himself incapable of feeling the most complete pleasure in life, we call him immoral.

A man entirely isolated does not exist in nature. We are born weak and incapable of satisfying our needs and at once come into relations with the human being who feeds us and protects us. The child, although egoistic, becomes attached to his protector, and in this way the feeling of sympathy is born. Guided by this feeling as well as by the sense of his own interest, the child soon begins to employ his will in restraining some of his instincts, which, none the less, are quite natural. Thus, the fear of being deprived of food makes him obedient to his protectors. The child cannot complete his normal cycle without pursuing a certain moral conduct.

When he becomes adult, man experiences the instinctive need of relations with someone of the other sex. This need lays certain duties on him, and although the love of a young man is less egoistical than that of the child, it is far from presenting the characters of self-abnegation and sacrifice.

A young woman, after having passed through the usual cycle of life with her mother and with a man, becomes herself a mother. Maternal instinct furnishes her with certain rules of conduct, but this natural instinct is not enough to fulfil its object, that is to say, to rear the child until an age when it can live independently. Directed by a feeling of sympathy for her child, the young mother learns from women with more experience to ward off dangers from her child. In the first years, moral conduct on the part of the mother consists almost entirely in bringing up the child in a healthy way. For this purpose she must acquire much knowledge. If she remains ignorant, her conduct must be regarded as immoral.

So far as concerns the bringing up of a child, the moral problem is quite simple, because we are all agreed that the object is to rear the child to maturity in the healthiest possible condition. When the child exhibits any habits harmful to this object, although due to natural instincts, the mother applies her knowledge to restrain them without paying attention to the theory that happiness consists in the fulfilment of everything that is natural. When a child has passed through the perilous first period of its life, the mother has to ask what general object she is to follow in its education. She wishes her child to be as happy as possible. Here the conception of orthobiosis will serve her, and it will teach her that the greatest happiness consists in the normal evolution of the sense of life, leading to serene old age, and finally reaching the fulness of satiety of life. Man, who has passed his apprenticeship to life from his birth, with his protectors, and, later on, with persons of the other sex, inevitably acquires certain elements necessary for social life. Persuaded that in order to succeed in his individual life he must have help from his fellows, he learns to subdue his anti-social tendencies, at first in his own interests. Let me take an example of this. When a man has reached a certain stage of civilisation, it generally becomes impossible to him to supply his bodily wants without the help of persons less cultured than himself. He takes into his house one or more servants, with whom he enters into definite relations. He wishes for himself and those about him a normal life, such as I have described in _The Nature of Man_. To attain this it is indispensable in his own interest and in that of his family, that his domestic servants should be well treated. The health of the family very often depends on the conduct of the servants, who will follow conscientiously the hygienic rules only if they themselves are living in good conditions. The custom according to which the masters live in luxuriously furnished rooms, while their servants have mean quarters in the attics, is immoral from the point of view of the well-being of the masters themselves. The crowded servants’ quarters are a nest of all sorts of infection, which may spread in the families of the masters. Very often people who think that they are following the rules of exact hygiene contract diseases without knowing that the infection has come from their servants.

Anger gives us another example. It is certainly harmful to the health, and so should be controlled in the interest of the bad-tempered person himself. Fits of rage are frequently followed by ruptures of blood-vessels, and by diabetes, and even cataracts have developed after some violent passion.

Luxurious habits are also well known to be harmful to the health. Heavy meals, evenings passed in the theatre and in society may seriously affect activity of the organs. Moreover, the luxury of some people is often the cause of misery to others. The knowledge that luxurious habits shorten life and prevent man from reaching the greatest happiness may warn people against luxury better than the appeal to the feeling of sympathy.

As it is a fact that most men guide their lives generally from egoistic motives, any theory of morality which is to be put into practice must reckon seriously with this factor. All other systems have recognised it. In the Sermon on the Mount, which is a summary of Christian morality, each moral act is recognised on the ground that it will bring some reward or obviate some punishment. “Rejoice,” said Jesus, “and be exceeding glad; for great is your reward in heaven” (Matt. v., 12). “Take heed that ye do not your alms before men, to be seen of them; otherwise ye have no reward of your Father which is in heaven” (Matt. vi., 1). “That thine alms may be in secret; and thy Father which seeth in secret himself shall reward thee openly” (Matt. vi., 4). “Judge not, that ye be not judged” (Matt. vii., 1). “But if ye forgive not men their trespasses, neither will your Father forgive your trespasses” (Matt. vi., 15). Jesus had no high opinion of the influence of altruism on human conduct.

Herbert Spencer in his treatise on morality (_The Data of Ethics_) also insists that laws of conduct, to be of general application, must not require men to make too great sacrifices, as otherwise the best teaching would remain a dead letter. He imagines, however, that in the future the human race will be so much improved that moral conduct will become instinctive, needing no compulsion. The English philosopher presents a view of the future of the human race totally at variance with the Kantian conception. Instead of human beings becoming filled with a sense of duty opposed to their natural instincts, the world will be peopled with men acting morally from inclination, so making the world delightful.

The ideal is so far removed from existing conditions that the possibility of its attainment is hardly worth considering. It is probable that a world whose inhabitants had the feeling of sympathy very highly developed would not be so delightful. For sympathy is generally a reaction against evil. When evil disappears, sympathy would be not merely useless, but annoying and harmful.

George Eliot in _Middlemarch_ describes a young woman enthusiastically anxious to do good to her fellows. When she came to live in a village, she made great plans to succour its poor. Her disillusion and annoyance were great when she found that the villagers were quite comfortably off, and had no need of her charity.

John Stuart Mill in his _Autobiography_ relates that when he was young he dreamed of reforming society and making everyone happy. But when he asked himself if the accomplishment of his beautiful ideas would make him happy, he was compelled to answer “No!” and this discovery plunged the young philosopher into a lamentable condition. He described himself as quite overcome, all that supported him in life crumbling away. His happiness could lie only in the constant pursuit of his object, and the charm seemed broken, because if attainment were not to please him, how could the means be of any interest to him? It seemed to him that nothing was left to which he could dedicate his life.

As it is highly probable that with the advance of civilisation the greatest evils of humanity will become lessened, and may even disappear, the sacrifices to be made will also become less. Now that there is a serum which protects against plague, there is no room for the heroism of the doctors who used to incur the greatest danger in fighting epidemics. Until lately doctors used to risk their life in treating the throats of diphtheric patients. A young doctor who was a friend of mine, of high ability and promise, died from diphtheria contracted under these conditions. He met his death, in isolation from his friends in case of infecting them, with the utmost heroism. Now that the anti-diphtheric serum has been discovered, such heroism would be unnecessary. The advance of science has removed the occasion of such sacrifices.

It is now very long since there has been opportunity for the heroism which steeled the hand of Abraham to sacrifice his only son to his religion. Human sacrifice, based on the highest morality, has become more and more rare, and will finally disappear. Rational morality, although it may admire such conduct, has no use for it. So also, it may foresee a time when men will be so highly developed that instead of being delighted to take advantage of the sympathy of their fellows, they will refuse it absolutely. Neither the Kantian idea of virtue, doing good as a pure duty, nor that of Herbert Spencer, according to which men have an instinctive need to help their fellows, will be realised in the future. The ideal will rather be that of men who will be self-sufficient and who will no longer permit others to do them good.

IV

ORTHOBIOSIS

Human nature must be modified according to an ideal—Comparison with the modification of the constitution of plants and of animals—Schlanstedt rye—Burbank’s plants—The ideal of orthobiosis—The immorality of ignorance—The place of hygiene in the social life—The place of altruism in moral conduct—The freedom of the theory of orthobiosis from metaphysics

As I have shown in _The Nature of Man_, the human constitution as it exists to-day, being the result of a long evolution and containing a large animal element, cannot furnish the basis of rational morality. The conception which has come down from antiquity to modern times, of a harmonious activity of all the organs, is no longer appropriate to mankind. Organs which are in course of atrophy must not be reawakened, and many natural characters which perhaps were useful in the case of animals must be made to disappear in men.

Human nature, which, like the constitutions of other organisms, is subject to evolution, must be modified according to a definite ideal. Just as a gardener or stock raiser is not content with the existing nature of the plants and animals with which he is occupied, but modifies them to suit his purposes, so also the scientific philosopher must not think of existing human nature as immutable, but must try to modify it for the advantage of mankind.

As bread is the chief article in human food, attempts to improve cereals have been made for a very long time. Rimpau made one of the greatest steps in this direction when he introduced into cultivation a variety of rye known as Schlanstedt rye, now fairly abundant in France and Germany. Rimpau set himself the task of producing a variety with the longest ears and containing many and heavy grains. Having conceived his ideal, he began to seek out what was nearest to it in a very large number of examples of rye. After patient and continued labour, using careful selection and cross-fertilisation, Rimpau succeeded in making the new variety, and so did a great service to mankind.

Burbank,[230] an American horticulturist, has recently gained a wide reputation because of his improvements of useful plants. He has produced a new kind of potato which has raised the value of potato crops in the United States by about £3,500,000 per annum. Burbank cultivated great numbers of fruit trees, flowers, and all kinds of plants, with the object of increasing their utility. One of his objects was to produce varieties which could resist dry conditions, which reproduced rapidly and so forth. He has modified the nature of plants to such an extent that he has cactus plants and brambles without thorns. The succulent leaves of the former provide an excellent food for cattle, whilst the absence of thorns in the latter makes their pleasant fruit more suitable for gardens. Burbank has enormously improved the production of stoneless plums, and has very much reduced the price of many bulbs and lilies by increasing their productivity.

To obtain such results much knowledge and a long period of time were necessary. To modify the nature of plants it was necessary to understand them well. To frame the new ideal of the plant it was necessary not only to have an exact conception of what was wanted, but to find out if the qualities of the plants in question furnished any hope of realising it.

The methods which have been successful in the case of plants and animals must be much modified for application to the human race. In the case of human beings the selection and cross-breeding which were imposed upon rye and plum trees are not possible, but, at the same time, the ideal of human nature, towards which mankind ought to press, may be formed. In our opinion this ideal is orthobiosis, that is to say, the development of the human life so that it passes through a long period of old age in active and vigorous health, leading to the final period in which there shall be present a sense of satiety of life, and a wish for death. I do not think that the ideal should be that of Herbert Spencer, a simple prolongation of human life. When the instinct of death comes at a not very late period of life, there would be no inconvenience in shortening the life, if death did not come soon after the appearance of the instinct. Probably this would be the only case where suicide was justified in the conception of orthobiosis.

The foregoing is the case of an action in conformity with the ideal, but quite contrary to human nature as it is at present. A similar contradiction appears in reproduction. Man came from animals amongst which unlimited reproduction was an important factor in the preservation of the species, as it allowed the species to survive under all sorts of bad conditions, such as diseases, combats, attacks of enemies, and changes of climate. Although man, according to the laws of human nature, is capable of reproducing extremely rapidly, the ideal of his happiness makes a restriction of this power necessary. Thus orthobiosis, based upon knowledge of human nature, would set limits to a function which is perhaps the most natural of all. The restriction which is already partially adopted will come more and more into operation as the struggle against diseases, the prolongation of human life, and the suppression of war make progress. It will be one of the chief means of diminishing the most brutal forms of the struggle for existence, and of increasing moral conduct amongst mankind.

Just as Rimpau began to study the nature of plants before trying to realise his ideal, so also varied and profound knowledge is the first requisite for the ideal of moral conduct. It is necessary not only to know the structure and function of the human organism, but to have exact ideas on human life as it is in society. Scientific knowledge is so indispensable for moral conduct that ignorance must be placed among the most immoral acts. A mother who rears her child in defiance of good hygiene, from want of knowledge, is acting immorally towards her offspring, notwithstanding her feeling of sympathy. And this also is true of a Government which remains in ignorance of the laws which regulate human life and human society.

It must be well understood that I am not here thinking of written knowledge, set down in treatises and volumes. Rimpau and Burbank went outside manuals of botany to obtain their knowledge. Besides books, wide ideas on the practice of life are required to direct aright the conduct of men. A doctor who has just finished his studies at the hospital, notwithstanding all his knowledge, is not yet sufficiently trained to be a good practitioner. He must acquire the habit of treating patients, and for this years are required. So also is it with regard to the practical applications of the principles of morality. The regulation of conduct requires profound knowledge both theoretical and practical, and men selected to frame or to apply laws of morality must have this double qualification. If the human race come to adopt the principles of orthobiosis, a considerable change in the qualities of men of different ages will follow. Old age will be postponed so much that men of from sixty to seventy years of age will retain their vigour, and will not require to ask assistance in the fashion now necessary. On the other hand, young men of twenty-one years of age will no longer be thought mature or ready to fulfil functions so difficult as taking a share in public affairs. The view which I set forth in _The Nature of Man_ regarding the danger which comes from the present interference of young men in political affairs has since then been confirmed in the most striking fashion.

It is easily intelligible that in the new conditions such modern idols as universal suffrage, public opinion, and the _referendum_, in which the ignorant masses are called on to decide questions which demand varied and profound knowledge, will last no longer than the old idols. The progress of human knowledge will bring about the replacement of such institutions by others, in which applied morality will be controlled by the really competent persons. I permit myself to suppose that in these times, scientific training will be much more general than it is just now, and that it will occupy the place which it deserves in education and in life.

It is equally clear that if a mother is to act morally with regard to her child, she must teach herself properly. In place of mythology and literature, she must learn hygiene and all that relates to the rational rearing of children. So, also, in the education of men, the study of the exact sciences must occupy by far the most important place. Then only will moral conduct and scientific knowledge begin to unite. An ignorant mother will bring up a child very badly notwithstanding all her good will and her affection. A doctor, however imbued with strong sympathy for his patients, could do them much harm if he had not the appropriate knowledge. Are not politicians open to the reproach from the point of view of morality that very often through ignorance they do the very worst evil in public administration? With the progress of knowledge, moral conduct and useful conduct will become more and more closely identified.

I have been reproached because in my system the health of the body occupies too large a place. It cannot be otherwise, because health certainly plays the chief part in existence. Notwithstanding his pessimism, Schopenhauer was convinced that health was the greatest treasure, a treasure before which everything else yielded. In many religions care of the health is laid down amongst the chief duties. Although many scientific men do not hold the opinion that circumcision was ordained for hygienic reasons, it is certain that hygiene was extremely important in the Jewish religion. It is only in Christianity, which despises the human body, that hygiene is excluded from the religious code, as in the words of Jesus:-

“Take no thought for your life, what ye shall eat, or what ye shall drink; nor yet for your body, what ye shall put on. Is not the life more than meat, and the body than raiment?” (Matt. vi., 25). As for long ages hygiene was very imperfectly known, it is not surprising that it played a small part in human affairs. Probably the objection to the importance that I assign to it in orthobiosis is a relic from the old order of things. Now, however, the situation is different. Bacteriology has placed hygiene on a scientific foundation, so that the latter is now one of the exact sciences. It has now become necessary to give it the chief place in applied morality as it is the branch of knowledge that teaches how men ought to live.

It has been objected that I have left no place for altruism in my system.[231] Certainly I have tried to find an egoistic basis for moral conduct, as I have shown above. I think, however, that the wish to live according to the ideal of orthobiosis and to make others live a normal life would be a powerful agency in improving social life, in preventing mutual damage, and promoting mutual help. Such a motive, within the reach of persons whose altruistic feelings are not specially strong, must largely extend moral conduct amongst human beings, and even although in future such manifestations of high morality as the sacrifice of life and health will become wholly or nearly wholly useless, I think that for the present there is still room for altruism. The practical application of scientific knowledge already gained admits much self-denial and good feeling. Struggle against prejudices of all kinds and the development and diffusion of sound ideas require a conduct very highly altruistic.

The fears of my opponents are still less justified when we reflect that the feelings of sympathy and of cohesion must play a large part in the business of helping the evolution of man towards the goal of normal life.

Although our actual knowledge already provides a basis of rational morality, it may be admitted that in the future, if science continues its forward march, the rules of moral conduct will become still more improved. There will be no ground for reproaching me for a blind faith in the all-powerfulness of science. Much more trust can be given to one who has faithfully carried out his promises, than to one who has promised much and fulfilled nothing. Science has already justified the hopes which have been placed in it. It has saved people from the most terrible diseases, and has made life much easier. On the other hand, religions, which demand an uncritical faith as the means of curing the ills which afflict humanity, have not fulfilled their promises.

The reproach that I preach blind faith in the progress of science, destined to replace religious faith, is unjust, because my faith depends on a confidence that science has already deserved. Equally unjust is the reproach that I have built my system on a partly metaphysical principle. According to M. Parodi,[232] the hypothesis of physiological old age and of natural death seem to “involve the idea of a natural duration of human life, which, however, from accidental reasons man does not complete at present. M. Metchnikoff repeatedly uses the expression ‘normal cycle.’ Now do we not see here the surreptitious repetition of the old teleological conception of nature, although at first he so energetically disavowed it? It is the belief that the species is a necessary reality, corresponding to a definite type of its own, in fact a special design of nature; that nature, to guide herself, had an ideal which circumstances could mistake or degrade, but which had to be restored to its perfect form? Otherwise, why does he insist that there must be a condition of perfect and stable equilibrium between individual and environment? that there is a normal cycle and that it must be possible to harmonise the disharmonies?”

I can show easily that all these objections rest upon a simple misunderstanding. I have never conceived of the existence of any ideal of nature or of the inevitable necessity of transforming disharmonies to harmonies. I have no knowledge of the “designs” and “motives” of nature; I have never taken my stand on metaphysical ground. I have not the remotest idea if nature has any ideal and if the appearance of man on the earth were a part of such an ideal. What I have spoken of is the ideal of man corresponding to the need to ward off the great evils of old age as it is now, and of death as we see it around us. I have said, moreover, that human nature, that collection of complex features of multiple origin, contains certain elements which may be used to modify it according to our human ideal. I have done nothing but what the horticulturist does when he finds in the nature of plants elements which suggest to him to try and make new and improved races. Just as the constitution of some plum trees contains elements which make it possible to produce plums without stones which are pleasanter to eat, so also in our own nature there exist characters which make it possible to transform our disharmonious nature into a harmonious one, in accordance with our ideal, and able to bring us happiness. I have not the smallest idea what ideal nature may have on the subject of plums, but I know very well that man has such designs and such an ideal as form a point of departure for the transformation of the nature of plums. Substitute man for the plum tree and you are at my point of view. When I have spoken of the normal cycle of life or of physiological old age, I have used the words normal and physiological only in relation to our ideal of the human constitution. I might just as well have said that a cactus without thorns is the normal cactus in the conditions where it was desired to obtain a succulent plant useful as food for cattle. The words “normal” and “physiological” seemed to me more convenient than such a phrase as “in correspondence with human ideals.”

I am so little convinced of the existence of any disposition of nature to transform our ills into goods, and our disharmonies into harmonies, that it would not surprise me if such an ideal were never reached. Even in unmetaphysical circles it is said that nature has the intention of preserving the species at the expense of the individual. The ground of this is that the species survives the individual. On the other hand, very many species have completely disappeared. Amongst these species were animals very highly organised, such as some anthropoid apes (_Dryopithecus_, etc.). As nature has not spared these, how can we be certain that she is not ready to deal with the human race in the same way. It is impossible for us to know the unknown, its plans and motives. We must leave nature on one side and concern ourselves with what is more congruous with our intelligence.

Our intelligence informs us that man is capable of much, and for this reason we hope that he may be able to modify his own nature and transform his disharmonies into harmonies. It is only human will that can attain this ideal.

FOOTNOTES:

[1] Westergaard, _Mortalitaet u. Morbilitaet_, 2nd. Edit., 1901, pp. 653-655.

[2] The volume of the urine excreted in 24 hours (in January 1905) was 500 c.c., with a density of 1019. There was no albumen or sugar. The quantity, per litre, of urea was 11·50 gr., of chlorides 9 gr., of phosphates 1·15 gr. The sediment contained crystals of uric acid, some pavement epithelium cells, a very few cells from the tubules, some hyaline platelets and isolated white corpuscles.

[3] _Extinct Animals_, London, 1905, pp. 28, 29.

[4] _Rendiconti d. Accad. d. Lincei_, 1906, vol. xiv. pp. 351, 390.

[5] _Ueb. d. physiologische Degeneration bei Actinosphærium eichhornii._ Jena, 1904.

[6] “Senescence and Rejuvenation,” _Journal of Physiology_, 1891, t. xii.

[7] _Biologisches Centralblatt_, 1904, pp. 65, 81, 113.

[8] _Comptes rendus de l’Académie des sciences_, 23 April, 1900.

[9] _Revue générale des sciences_, 30 Dec., 1904, p. 1116.

[10] _Le Bulletin médical_, 1906, p. 721; _Le Cerveau sénile_, Lille, 1906, pp. 64-69.

[11] _Mémoires couronnés publiés par l’Académie royale de Belgique_, Bruxelles, 1906.

[12] _Revue de Médecine_, Nov., 1906, p. 870.

[13] _Annales de l’Institut Pasteur_, Oct. 1906, p. 859.

[14] _Annales de l’Institut Pasteur_, 1900, vol. xiv. p. 113.

[15] _Eléments d’histologie humaine_, French translation, 1856, p. 222.

[16] _Leçons sur la physiologie du système nerveux_, 1866.

[17] _De la dégenérescence graisseuse des muscles chez des vieillards._ Paris, 1867.

[18] Demange, _Étude sur la vieillesse_, 1886, p. 118.

[19] _C. R. de la Société de Biologie_, 14 November, 1903.

[20] _Clinica medica_, 1905, _n._ 6.

[21] _Bulletins de la Société royale des sciences-medicales de Bruxelles_, 1905, _n._ 4, p. 105.

[22] Sarbach, _Mittheilungen a. d. Grenzgeb. d. Med. u. Chir._, vol. xv. 1906.

[23] _Verhandlungen d. Kongr. f. innere Medicin._ Wiesbaden, 1906, pp. 59, 98.

[24] _Archives de Neurologie_, 1886.

[25] Die Function d. Schilddrüse, _Virchow’s Festschrift_, vol. i. 1891, p. 369.

[26] Fuss, Der Greisenbogen, in _Virchow’s Archiv_, 1905, vol. clxxxii. p. 407; S. Toufesco, _Sur le cristallin_, Paris, 1906.

[27] Edmond Fournier, _Stigmates dystrophiques de l’hérédosyphilis_, Paris, 1898, p. 4.

[28] _Histoire naturelle générale et particulière_, vol. ii. Paris, 1749.

[29] _De la longévité humaine et de la quantité de vie sur le globe_, Paris, 1855.

[30] _Ueber die Dauer des Lebens_, Jena, 1882, p. 4.

[31] Brehm, _La vie des animaux, Mammifères_, vol. ii. p. 623.

[32] _Leçons sur la physiologie et l’anatomie comparée_, vol. ix. 1870, p. 446.

[33] _Archiv f. die gesammte Physiologie_, Bonn, 1903, vol. xcv. p. 606.

[34] _La Nature_, May 12, 1900, p. 378.

[35] Ashworth and Annandale, _Proceedings of the R. Society of Edinburgh_, vol. xxv. part iv. 1904.

[36] _Bronn’s Klassen u. Ordnungen des Thierreichs_, vol. iii. p. 466.

[37] Weismann, _The Duration of Life_, in “Essays on Heredity” (English translation), Oxford, 1889.

[38] Oustalet, “_La Longévité chez les Animaux vertébrés_,” _La Nature_, May 12, 1900, p. 378.

[39] “_On the Comparative Ages to which Birds live_,” _The Ibis_, Jan., 1899, vol. v. p. 19.

[40] J. Maumus, “Les cæcums des oiseaux,” _Annales des sciences naturelles_, 902. See also P. Chalmers Mitchell, “On the Intestinal Tract of Birds,” _Trans. Linnæan Soc. of London_, vol. viii. part 7, 1901.

[41] Weidersheim, _Elements of the Comparative Anatomy of Vertebrates_, translated by W. Newton Parker, p. 236, 1886.

[42] _Elements of Comparative Anatomy_, English translation by F. Jeffrey Bell, B.A., London, 1878, p. 562.

[43] _Virchow’s Archiv_, 1869, vol. xlviii. p. 151.

[44] P. Chalmers Mitchell, “On the Intestinal Tract of Mammals,” _Trans. Zool. Soc. of London_, vol. xvii. part 5, 1905.

[45] _Travaux de la Société des médecins russes à Saint-Pétersbourg._ September-October, 1905, p. 18 (in Russian).

[46] _Virchow’s Archiv_, 1874, vol. lix, p. 161.

[47] _Zeitschrift f. klinische. Medicin_, 1887, vol. xii.

[48] _Mittheilungen a. d. Grenzgebieten d. Medicin u. Chirurgie_, 1905, vol. xiv.

[49] Aldor, _Centralblatt f. innere Medicin_, 1898, p. 161.

[50] _L’année biologique_, 7th year, 1902. Paris, 1903, p. 590.

[51] _Gazette des Hôpitaux_, 1904, p. 715.

[52] _Accidents dus à la Constipation pendant la Grossesse, l’Accouchement et les Suites des Couches._ Thèse, Paris, 1902, p. 32.

[53] _Comptes rendus de l’Académie des Sciences_, Paris, 1905, 10 July, p. 136.

[54] _Archiv. f. klinische Chirurgie_, 1901, vol. lxiii, p. 773.

[55] Kolle u. Wassermann, _Handb. d. pathogenen Mikro-organismen_, vol. ii, 1903, p. 678.

[56] Ficker, in the _Archiv. für Hygiene_, vol. lii, p. 179, has recently published the results of an investigation into this.

[57] Quoted by Frédericq et Nuel, _Eléments de physiologie humaine_, 4th edition, 1899, p. 256.

[58] Quoted by Frédericq et Nuel, _op. cit._

[59] _L’aviculture_ (a fortnightly Russian journal), Oct. 1st, 1904, No. 19, p. 3.

[60] _Country Life_, 1905.

[61] Quoted by Ebstein, _Die Kunst d. mensch. Leben zu verlängern_, 1891.

[62] _Op. cit._, p. 12.

[63] _Annuaire statistique de la ville de Paris_, 23rd year, 1904, p. 164-171.

[64] Ornstein, Virchow’s _Archiv._, 1891, vol. cxxv, p. 408.

[65] Ebstein, _op. cit._, p. 70.

[66] Lejoncourt, _Galerie des centenaires_, Paris, 1842, p. 96-98.

[67] Lejoncourt, _op. cit._, p. 101.

[68] _Researches into the Physical History of Mankind_, 1836, vol. i, p. 1157.

[69] I owe to the kindness of M. Chemin a memoir in which he has brought together the ancient and new records on the centenarians of all countries up to the end of the nineteenth century. M. Chemin was unable to find a publisher, but has given me his manuscript, extending to 182 pages.

[70] _Ueber die Kunst d. Verlängerung d. mensch. Lebens_, Bonn, 1890, p. 23.

[71] _Physiologie générale_, 1900, p. 381.

[72] _Tableaux de la nature_ (French translation), 1808, vol. ii, p. 109.

[73] Webb and Berthelot, _Histoire naturelle des îles Canaries_, 1839, vol. i, part 2, pp. 97-98.

[74] _Bibliothèque universelle de Genève_, 1839, vol. xlvi, p. 387.

[75] _Ibid._, p. 392.

[76] _Bibliothèque universelle de Genève_, vol. xlvii, p. 49.

[77] _Entstehung u. Begriff d. naturhistorischen Art_, 2nd edit., Munich, 1865, p. 37.

[78] Griesebach, _Die Vegetation der Erde_.

[79] Batalin, _Acta Horti Petropolitani_, vol. xi, no. 6, 1890, p. 289.

[80] I am indebted to Prof. Hugo de Vries for this and other instances of the prolongation of life in plants.

[81] Engler’s _Botanische Jahrbücher_, Leipzig, 1882, vol. ii, p. 51.

[82] _Organographie der Pflanzen_, Iéna, 1898-1901.

[83] _Bulletin du jardin botanique de Bruxelles_, vol. i, no. 6, 1905.

[84] Hugo de Vries, _Jahrbücher für wissensch. Botanik_, 1890, vol. xxii, p. 52.

[85] _Annales de l’Institut Pasteur_, 1902, p. 71.

[86] Duclaux, _Microbiologie_, vol. iii, 1900, p. 460.

[87] _Archiv. für Anatomie und Physiologie_, 1864.

[88] _Archives de Zoologie expérimentale_, 1901, vol. ix, p. 81.

[89] Observations of Dr. Speyer, quoted by Weismann.

[90] See _The Nature of Man_.

[91] _Étude clinique sur la vieillesse_, Paris, 1886, p. 145.

[92] _Revue scientifique_, 1877, p. 1173.

[93] _Revue scientifique_, 1887, 2nd part, p. 105.

[94] Gabriel Bertrand, _Annales de l’Institut Pasteur_, 1904, p. 672.

[95] _Therapeutische Monatshefte_, 1904, p. 193.

[96] _Münchener medicinische Wochenschrift_, 1904, No. 1; _Verhandlungen der physiologischen Gesellschaft zu Berlin_, Dec. 5th, 1904.

[97] _Archives des sciences physiques et naturelles_, Geneva, March, 1905, vol. xvii; _Archives de physiologie_, vol. iv, p. 245.

[98] Laveran and Mesnil, _Trypanosomes et Trypanosomiases_, Paris, 1904, p. 328.

[99] Paris, 1834, 4th edition, vol. ii, p. 118.

[100] _Revue de métaphysique et de morale_, March, 1904.

[101] _Année biologique_, vol. vii, p. 595.

[102] _Revue occidentale_, July 1st, 1904, vol. xxx, p. 87.

[103] Egger, “_Le moi des mourants_,” Revue philosophique, 1896, i, p. 27.

[104] _Ibid._, pp. 303-307; v. also _Bulletin de l’Institut général phycholog._, 1903, p. 29.

[105] Cicero, _Tusculanes_, chap, xxviii.

[106] Rapport de M. Bienvenu-Martin à la Chambre des députés, Paris, 1903.

[107] _L’Art de prolonger la vie humaine_ (French translation), Lausanne, 1809, p. 5.

[108] A. Réville, _Histoire des religions_, vol. iii, Paris, 1889, p. 428.

[109] A. Réville, _loc. cit._, p. 455.

[110] _Comptes rendus de la Societé de Biologie_, 1899, p. 415.

[111] _Deutsche medicin. Wochenschrift_, 1891, p. 1027.

[112] _Die physiologisch-chemisch. Grundlagen d. Spermintheorie_, Berlin, 1898.

[113] _British Medical Journal_, 1904; _Deutsche Mediz. Wochenschr._, 1904, Nos. 18-21.

[114] _Die Lehre von d. Mortalitaet u. Morbilitaet_, 2nd edition, Jena, 1901.

[115] _Medizinische Klinik_, 1905, No. 22.

[116] _Die experimentelle Syphilisforschung_, Berlin, 1906, p. 82.

[117] _Annales de l’Institut Pasteur_, 1900, pp. 369-413.

[118] _Les sérums hemolytiques_, Lyon, 1903.

[119] According to a recent publication of M. Ellenberger (_Archiv. f. Anatomie u. Physiologie, Physiologische Abtheilung_, 1906, p. 139), the cæca of the horse, pig and rabbit, play an active part in the digestion of vegetable matter, which is rich in cellulose. At the end of his treatise, Ellenberger insists that the vermiform appendix of the cæcum is not a rudimentary organ. The reason why the appendix can be removed in the case of man without disturbance to the functions of the body, is that this work can be performed by the Peyer’s patches of the intestine. The existence of the appendix is not necessary to the normal processes of the body, and is a real danger to health and sometimes to life. Comparative study of the cæca in birds shows that these organs are in process of degeneration.

[120] _Archiv. für experimentelle Pathologie_, vol. xxviii, p. 311.

[121] _Sixième Congrès de Chirurgie_, Paris, 1903, p. 86.

[122] _Leçons sur les auto-intoxications_, Paris, 1886.

[123] _Zeitschrift für Hygiene_, 1892, vol. xii, p. 88.

[124] _Zeitschrift für klinische Medicin_, 1903, vol. xlviii, p. 491.

[125] There is a summary of this question in Gerhardt’s work on intestinal putrefaction, in _Ergebnisse der Physiologie_, 3rd year, section 1, Wiesbaden, 1904, pp. 107-154.

[126] _The A B C of our Nutrition_, New York, 1903; Dr. Regnault, Nov. 1, “L’art de manger,” _La Revue_, 1906, p. 92.

[127] _Zeitschr. f. diatetische u. physikal. Therapie_, t. viii, 1904, 1905.

[128] _Du Cap au lac Nyassa_, Paris, 1897, pp. 291-294.

[129] Gaffky and Paak, in _Arbeiten d. k. Gesundheitsamtes_, vol. vi, 1890.

[130] _Annales de l’Institut Pasteur_, 1903.

[131] Cormouls-Houlès, _Vingt-sept années d’agriculture pratique_, Paris, 1899, pp. 57-58.

[132] _British Medical Journal_, 1897, Dec. 25th, p. 1898.

[133] _Comptes rendus de la Soc. de Biologie_, 1906, March 17th.

[134] Dr. Combe, _L’auto intoxication intestinale_, Paris, 1906. This valuable work contains much useful information on the subject.

[135] Grundzach, _Zeitschrift für klinische Medezin_, 1893, p. 70; Schmitz, _Zeitschrift für physiologische Chemie_, 1894, vol. xix, p. 401; Singer, _Therapeutische Monatshefte_, 1901, p. 441.

[136] _Journal für praktische Chemie_, 1882, vol. xxvi, p. 43.

[137] _Archiv. für experimentelle Pathologie_, 1883, vol. xvii, p. 442.

[138] In the English authorised version as in the translation of Osterwald the word “butter” is used in place of “soured milk.” Professor Metchnikoff follows the translation given by Ebstein in his work on the Medicine of the Old Testament.

[139] _Presse médicale_, 1904, p. 619.

[140] “An authentic narrative of the loss of the American brig _Commerce_ wrecked on the western coast of Africa in the month of August, 1815, with an account of the sufferings of the surviving officers and crew, who were enslaved by the wandering Arabs on the African desert or Zaharah; and observations historical, geographical, etc.” by James Riley. Hartford, S. Andrus and Son, 1854.

[141] _Arbeiten a. d. k. Gesundheitsamte_, 1889, vol. v, pp. 297-304.

[142] See Grasberger and Schattenfroh, _Archiv. für Hygiene_, 1902, vol. xlii, p. 246.

[143] _Annales de l’Institut Pasteur_, 1902, p. 65.

[144] _Revue médicale de la Suisse romande_, 1905, p. 716.

[145] _Comptes rendus de la Soc. Biologique_, March 17th, 1906.

[146] _Annales de l’Institut Pasteur_, 1906, p. 977.

[147] Soured milk can be taken at any time of the day, with or in between meals.

[148] _Jahrbuch für Kinderheilkunde, N. F. 12 Ergænsungsheft_, 1900.

[149] _Annales de l’Institut Pasteur_, 1905, p. 295; _Tribune médicale_, Feb. 24th, 1906.

[150] _La nature humaine et la philosophie optimiste_, Paris, 1904.

[151] _Archiv. f. Anat. u. Physiol., Anatom. Abtheil_, 1903, p. 205.

[152] _L’univers et la vie_, p. 592.

[153] Huxley, _Man’s Place in Nature_. Collected Essays, vol. vii, p. 54.

[154] _Ibid._, p. 60.

[155] _Ibid._, p. 62.

[156] _Ibid._, p. 67.

[157] Ménégaux, _Les Mammifères_, p. 24.

[158] Darwin, _Expression of the Emotions in Man and Animals_, 1873, p. 67.

[159] _Biologisches Centralblatt_, 1904, p. 475.

[160] J. de Fontenelle, _Nouveau manuel complet des nageurs_, Paris, 1837, p. 2.

[161] _La natation et les bains_, Paris, 1887.

[162] Quoted by M. Pitres in _Leçons cliniques sur l’hystérie_, 1891, vol. i.

[163] Bourneville et Regnard, _Iconographie photographique de la Salpétrière_, 1879-1880, vol. iii, p. 50.

[164] Stéphanie Feinkind, _Du somnambulisme dit naturel_, Paris, 1893, p. 55.

[165] _Dictionnaire des sciences médicales_, 1821, vol. lii, p. 119.

[166] _Du Sommeil non naturel_, Paris, 1886.

[167] _Conférence faite à la Société de l’Internat_, June 28th, 1906.

[168] _The Crowd: a Study of the Popular Mind._ English translation, London, 1896.

[169] _Souvenirs d’enfance de S. Kowalevsky_, 1895, pp. 301-311.

[170] W. Herzberg, _Sozialdemokratie und Anarchismus_, 1906, p. 17.

[171] _Le problème agraire_, 1905, p. 147.

[172] “The Coming Slavery” in _Man versus the State_, 1888, p. 18.

[173] _Human, too Human._ French translation, 1899, pp. 405-407. A German critic has reproached me for my ignorance of Nietzsche’s works. I have read several of them, but the mixture of genius and madness in them makes them difficult to use. In this connection Moebius’ volume, _Ueber das Pathologische bei Nietzsche_ (Wiesbaden, 1902), is of interest.

[174] Quoted by Oldenberg, _Le Bouddha_, French translation, Paris, 1894, p. 214.

[175] P. Régnaud, “Le pessimisme brahmanique,” in _Annales du Musée Guimet_, 1880, vol. i, pp. 110-111.

[176] Guyau, _La Morale d’Epicure_, 4th edition, 1904, p. 116.

[177] _Ad Marciam_, chap. x.

[178] _Poésies et œuvres morales_, by Leopardi. Translated into French 1880, p. 49.

[179] These facts are taken from Westergaard, 2nd edit., 1901, p. 649.

[180] Dieudonné, _Archiv für Kulturgeschichte_, 1903, vol. i, p. 357.

[181] Kowalevsky, _Studien zur Psychologie des Pessimismus_, Wiesbaden, 1904.

[182] _Medicinische Klinik_, 1906, n. 25 and 26.

[183] _Der Werth des Lebens._

[184] _Ueber Schopenhauer_, Leipzig, 1899.

[185] Moebius, _Goethe_, vol. i, Leipzig, 1903.

[186] V. Kunz, “Zur Blindenphysiologie,” _Wiener medicin. Wochenschrift_, 1902, No. 21.

[187] _Physiologie de la Lecture et de l’Écriture_, Paris, 1905.

[188] _Entre aveugles_, Paris, 1903.

[189] _Der Blindenfreund_, Feb. 15th, 1906.

[190] _Critical and Miscellaneous Essays_, vol. i, pp. 164-5, in the Essay on _Goethe_.

[191] _Briefwechsel zwischen Goethe und Zelter._ Letter of Dec. 3, 1812.

[192] Quoted in Moebius’ _Goethe_, vol. ii, p. 80.

[193] _The Fifth Roman Elegy_, Blaze’s French translation, 1873 p. 186. Some of Goethe’s biographers, and amongst them G. H. Lewes, maintain that these lines relate to Christine, Goethe’s wife. This is erroneous; they refer to Faustine (see Bielschowsky, i, p. 517).

[194] Moebius’ _Goethe_, vol. ii, pp. 84-87.

[195] Moebius’ _Goethe_, vol. ii, pp. 84-87.

[196] Quoted by Bode _in Goethe’s Lebenskunst_, Berlin, 1905, p. 59.

[197] _Ueber die Wirkungen d. Castration_, Halle, 1903, p. 82.

[198] _Comptes rendus de la Société de Biologie_, 1889, p. 420.

[199] The word _Samen_ of the original is the expression of the alchemists for the “principle of life.”

[200] Erich Schmidt, Goethe’s _Faust in ursprünglicher Gestalt_, 6th edit., Weimar, 1905, p. 1.

[201] _Faust_, Bayard Taylor’s translation. London: Warne & Co., pp. 20-21.

[202] _Op. cit._, p. 32.

[203] _Op. cit._, pp. 33, 34.

[204] Details of this will be found in Kuno Fischer’s _Goethe’s Faust_, pp. 328-330.

[205] _Op. cit._, pg. 36.

[206] _Op. cit._, pg. 45.

[207] _Op. cit._, p. 46.

[208] _Op. cit._, p. 46.

[209] _Op. cit._, p. 71.

[210] _Op. cit._, p. 51.

[211] _Op. cit._, p. 151.

[212] _Op. cit._, p. 203.

[213] _Op. cit._, p. 205.

[214] _Op. cit._, p. 230.

[215] _Op. cit._, p. 231.

[216] _Op. cit._, p. 284.

[217] _Op. cit._, p. 287.

[218] _Op. cit._, p 298.

[219] _Op. cit._, p. 305.

[220] _Op. cit._, p. 309.

[221] _Op. cit._, p. 313.

[222] _Op. cit._, p. 351.

[223] _Op. cit._, pp. 354-355.

[224] _Op. cit._, p. 365.

[225] _Op. cit._, p. 370.

[226] _V. Tribune médicale_, 1906, p. 449.

[227] _La Revue_, Nov. 15th and Dec. 1st.

[228] _Essais de Philosophie critique_, Paris, 1864.

[229] _System der Ethik_, 7th and 8th editions, vol. i, p. 199. Berlin 1906.

[230] De Vries, in _Biologisches Centralblatt_, 1906, Sept. 1st, p. 609.

[231] Dr. Grasset, “La fin de la vie” in the _Revue de philosophie_, Aug. 1st, 1903.

[232] “Morale et biologie,” _Revue philosophique_, 1904, vol. lviii, p. 125.

INDEX

Abelard, 273

Abraham, use of soured milk, 171

Ackermann, Mde., 237

_Actinosphærium_, degeneration in, 14

Adanson, on age of Baobab-tree, 98

Adrenaline, effect of, 121

Agave, duration of life of, 100

Aged, treatment of in uncivilised countries, 1, 2

Alcohol and longevity, 91, 92

Algeria, ostriches at, 76, 78, 79

Altruism, 331

Ambard, Dr., on Mde. Robineau, 7

Anæmia, of brain, and sleep, 122 use of serums in, 149

André, M., use of serums in anæmia, 149

Anger, 321

Annandale, Nelson, on age of anemones, 48

Annuals, change to biennials or perennials, 100 death of, 102

Antelopes, excreta of, 66

Anthropoids, mental characters of, 191 _et seq._

Antiseptics, use of, in intestinal putrefaction, 156

Ants, 220, 221

Apes, anthropoid, mental characters of, 191 _et seq._ relationship to man, 184, 185

Arabs, use of milk by, 174

Aristotle, 132

Arteries, sclerosis of, in the aged, 31

Ascidians, social, 219

Ashworth, Mr., on age of anemones, 48

Atheroma, in the aged, 30

Atrophy, of cells, 26 of muscles, 28

Auditory apparatus, rudimentary organism, 188

Augsburg, elixir of life, 138

Auto-intoxication, from intestinal putrefaction, 69 in plants, 107 sleep, due to, 120

Babinsky, Dr., hysteria a relic from apes, 209

Balkan States, centenarians frequent in, 90

Baobab-tree, age of, 98

Barth, Dr., definition of somnambulism, 206

Batrachia, longevity of, 50

Bats, intestinal flora of, 80, 81

Bees, 49, 220, 226

Beetroot, perennial variety of, 100

Belgium, old age pensions, 4

Bélonovsky, M., on serums in anæmia, 148

Bélonowsky, Dr., on Bulgarian bacillus, 170

Berthelot, on dragon-tree of Orotava, 96

Bertrand, M. G., on sorbose fermentation, 106

Bertrand and Weisweiler, on _Bacillus bulgaris_, 179

Besredka, M., on blood serums, 148, 149

Bielschowsky, biographer of Goethe, 269

Blanchard, E., on age of carp, 50

Birds, intestinal flora of, 76, 79 longevity of, 52

Blindness, 248, 257

Bloch, Dr. I., on Schopenhauer, 247

Blood-vessels, hardening of, in the old, 31

Bodio, on infant mortality, 85

Boerhave, on gerokomy, 136

Bones, degeneration of, 29, 30

Bordet, M. J. M., on serums, 148

Botulism, poison of, 70, 82

Bouchard, M., on disinfection of intestines, 156

Bouchet, M., on constipation after parturition, 68

Bourneville, M., on effects of extirpation of thyroid, 34

Boveri, M., produced atherana by nicotine, 32

Bone, marrow, in old age, 37

_Botryllus_, 219

Boutroux, definition of morality, 303

Bradyfagy, 159

Brain, anæmia of, as cause of sleep, 122

Brehm, on age of cattle, 55

Brettes, criticism of “rudimentary organs,” 186

Bricon, M., on effects of extirpation of thyroid, 34

Brigand, Calabrian, fear of death, 194, 195

Brillat-Savarin, quotation from, 126

Brown-Séquard, specific for long life, 139, 277

Brudzinsky, M., on use of lactic microbes, 181

Buddha, on pessimism, 233, 247

Buehler, Dr., on cause of old age, 16

Buffon, on duration of life, 40, 50

Bulgarian bacillus, 178, 179, 180, 181, 182

Bunge, on relation between growth and longevity, 42

Burbank, American horticulturist, 326, 328

Butterflies, longevity of, 57

Bütschli, O., on life of cells, 15

Byron, 239, 247, 295

Cachexia, after extirpation of thyroid gland, 34

Caeca, of vertebrates, 60 _et seq._

Cagliostro, elixir of life, 138

Calomel, as an intestinal antiseptic, 158 and syphilis, 146

Camphor, as an intestinal antiseptic, 156

Canary Islands, 96

Cancalon, Dr., on instinct of death, 128, 129

Cancer, and cleanliness, 144

Candolle, A. de, on cypresses of Mexico, 98 on age of trees, 99

Cantacuzène, M., on blood serums, 148

Capital punishment, 305

Carlyle, on “Werther,” 265

Castration, effects of, 272

Cats, longevity of, 56

Cattle, longevity of, 55

Celibacy, and education of women, 224

Cell reproduction, rate of, 16

Centenarians, 4, 5, 86, 88, 89, 175, 176

Charcot, on sterilised food, 162, 163 on hysteria, 202

Charron, M., on putrefactive poisons, 69

Chemin, M., on centenarians, 88, 89

Chimpanzee, 185, 192, 193

China, Emperor Chi-Hoang-Ti and immortality, 137

Chopin, a degenerate, 134

Christian morality, 321, 330

Chromophags, action of, 25

Claparède, E., on theory of sleep, 123, 124, 125

Cleanliness, and increase of life, 144

Clergymen, increasing duration of life of, 142

Coffee and longevity, 92

Cohausen, on gerokomy, 137

Cohendy, Dr. M., on Bulgarian bacillus, 178 on intestinal flora, 78, 79 on intestinal putrefaction, 168 on thymol as a disinfectant, 157

Collectivism, 228

Colon, absorption in, 64

Constipation, evil results of, 67, 68, 69

Cooking, effect of, on microbes in food, 162

Copenhagen, suicide in, 3

Coral polyps, 216

Cornaro, 91

Cossacks, and biennial rye, 100

Cretinism, compared with senility, 32

Crœsus, 197

Cryptogams, life of, 99

Cursorial birds, intestinal flora of, 76

Cypress, age of, 98

Czerny, M., on absorption in colon, 64 on cancer, 144

D’Alton, and Goethe, 280

Dalyell, old anemone of, 48

Dana, on _monstrilla_, 115

Darwin, on fear, 195

David, King, 136

Death, instinct of, 128, 129 natural, 94, 109, 119 sensations at approach of, 126, 127, 130

Debreuil, Ch., on defecation in rheas, 76 on excreta of antelopes, 66

Degenerates, famous, 134

Delage, Yves, criticism of instinct of death, 128 on function of large intestines, 65, 66

Demange, M., on old age, 119

Denmark, suicide in, 3, 237

Descent of man, 184

Despotism, and socialism, 230

de Vries, H., on duration of life of plants, 104 on prolongation of life of plants, 100 on natural death in plants, 101

Diet and longevity, 46

Digestive system and senility, 59

_Diplogaster_, mother killed by larvæ, 111

Diphtheria, 323

Disease, and shortening of life, 145 _et seq._

Doctors, lady, 225

Dodo, 213

Dogs, longevity of, 55

Dostoiewsky, quotation from, 2

Doyen, M., operation on double monsters, 216

Dragon-tree, of Orotava, 96, 97, 98

Drakenberg, age of, 87

Drunkenness, and morality, 317

_Dryopithecus_, 334

Ducks, old, 11

Duering, on pessimism, 248

Durand-Fardel, M., on atheroma, 30

Duration of life, in animals, 39 _et seq._, 133

Eagles, intestinal flora of, 82

Ecclesiastes, quotation from, 233

Eckermann, narrative of Goethe’s last years, 271, 274, 279

Egoism, 227, 306, 331

Egyptian milk, 105

Eimer, Th., on intestines of bats &c., 62, 63

Einhorn, Dr., on bradyfagy, 159

_Elective Affinities_, Goethe’s, 273

Elephants, 9, 54, 83, 197

Eliot, George, 322

_Elixir vitæ_, 138

Ellenberger, on digestion in horse, 78

Enriquez, on infusoria, 13

Ephemeridæ, duration of life of, 113, 118

Epicureans, 309

Epiphyses of bones, as giving period of growth, 40

Ermenghem, van, on botulism, 70

Errera, Dr., on cause of sleep, 121

_Eudoxia_, 218

Ewald, on absorption in colon, 64

Exhaustion, as cause of plant death, 104, 107

Extinction of animals, 213

Eye, in old age, 36

Fatigue, Weichardt on cause of, 123

“_Faust_” and Goethe, 283 _et seq._

Favorsky, Dr., on botulism, 82

Fear, analysis of, 194

Fecundity and duration of life, 43, 44, 45, 57, 58

Feinkind, case of somnambulism quoted from, 204

Femininist movement, 224

Fermentation, cause of, 105

Fertility and longevity, 44, 45

Fish, longevity of, 50

Flamans, M., 5

Fletcher, on chewing, 159

Flora, of intestines, poisonous effect of, 70, 73 _et seq._, 151 _et seq._

Flourens, on duration of life, 40, 84

Foà, on use of soured milk in Africa, 172

Food, evil effects of putrefaction in, 163

Fouard, M., on soured milk, 180

Fürbbinger, on Brown-Séquard’s emulsions, 139

Gautier, A., on leucomaines, 121

Gegenbaur, on intestinal tract, 60, 61

Genius and sexual power, 272

Gerokomy, 136

Gessner, on age of pike, 50

Gestation and longevity, 42

Giacomini, on Harderian gland, 189

Gibbons, 192, 198

Goebel, on duration of life of prothalli, 101, 102

Goethe, 260-300, 305

“Goose-skin,” 196

Gorilla, strength of, 192

Griesbach, on sense of touch in blind, 257

Grigoroff, on Bulgarian yahourth, 175, 178

Grindon, on age of sheep, 55

Guinon, Dr., on a case of hysteria, 203

Gurney, J. H., on longevity of birds, 51, 79

Haeckel, on medical selection, 134

Haffkine, M., 112

Hair, 17, 18

_Halictus_, a solitary bee, 226

Haller, on human longevity, 84, 132

_Hamlet_, quotation from, 239

Hannibal, his elephants swim the Rhone, 197

Harderian gland, 189

Hartmann, 235, 241

Harvey, on Parr, 87

Hayem, Prof., on use of lactic acid, 169, 173

Heart, diseases of, and syphilis, 145, 146

Hegesias, and suicide, 234

Heile, on absorption in colon, 64

Heim, on microbes in milk, 176

Heim, Prof., on Alpine accidents, 130

Heine, 236, 240

Hermippus, and gerokomy, 137

Herter, Dr., experiments on lactic acid in dogs, 167

Hertwig, R., on _Actinosphærium_, 14

Hildebrand, on duration of life of plants, 101, 102

Hippocrates, 132

Hofmeister, on digestion in horse, 74

Honey-ant, 222

Horse, cæcum, 62 digestion, 74 use of serum, 147

Horsley, Sir V., on effects of extirpation of thyroid, 34

Horst, on a somnambulistic soldier, 203

Hufeland, quotation from “Macrobiotique,” 137

Hugo, V., and sexuality, 277

Humboldt, on dragon-tree of Orotava, 96 on longevity of parrots, 52

Hunger, compared with sleep, 125

Huxley, on character of Orang, 193

Hygiene, and old age, 141, 142, 143

Hypnotism, of a crowd on individuals, 210

Hysteria, analysis of, 200 _et seq._ in monkeys, 208

Ibsen, and sexuality, 277

Idleness, 316

Immortality, Chinese beverage for, 137, 138

Incubation, duration of, compared with longevity, 41, 42

India, government of, and age of elephants, 54

Individualism, 316

Individuality, 212 _et seq._

Infusoria, death of, 95 senescence of, 13

Insects, ages of, 49 social, 220 _et seq._

Instinct, of death, 128, 129 maternal, 319, 320, 329 social, 306

Intestine, large, 59, 65, 67, 151

Intuitive theory of morality, 305

Jacobson, organ of, 187

Javal, Dr., on characters of the blind, 257, 259

Jenner, effect of vaccination on mortality rate, 144

Josué, M., artificial production of atheroma, 32

Jousset, Dr., on difference between man and apes, 184

Kant, 309, 310

Kautsky, on socialism, 229, 230

Kentigern, age of, 87

Kephir, 171, 172, 173

Khoury, M., on ferment of Egyptian milk, 105

Kocher, Dr., on effects of extirpation of thyroid gland, 33

Kocher, Prof., case of removal of large intestine, 152, 153

Kölliker, on degeneration of muscles, 27

Koppenfels, on character of gorilla, 194

Koumiss, 172

Kowalevsky, Sophie, 225

Kowalevsky, analysis of pessimism, 241, 255

Kukula, experiments on intestinal poisons, 69, 70

Kwass, 166

Lactic bacilli, and putrefaction in intestine, 168

Laignel-Lavastine, M., criticism of neuronophagy, 20

Lankester, Sir E. Ray, on longevity, 12, 56

Lao-Tsé, and immortality, 137

Laud, Archbishop, old tortoise of, 51

Lautschenberger, on absorption in colon, 64

Lavater, Goethe’s letter to, 268

Laws aiding the aged, 3, 4

“Leben,” Egyptian, 105, 171, 177, 178

Le Bon, G., on hysteria in crowds, 209

Lenau, M., 236

Lenthéric, on elephants swimming, 197

Leopardi, G., pessimistic poet, 235, 236, 247

Le Play, M., on putrefactive poisons, 69

Léri, M., on senile brain, 20

Lermontoff, 236

Leucomaines, as cause of sleep, 121

Levaillant, on longevity of parrots, 52

Lewes, G. H., on Goethe, 273, 290, 292, 298

Lexis, on duration of human life, 85

Life, duration of, in animals, 39 _et seq._

Life, prolongation of human, 132, _et seq._ “sense” of, 260

Lima, Dr., on use of soured milk in Africa, 172, 174

Lloyd, M., old anemone of, 47

Loewenberg, Dr., on Mde. Robineau, 7

London Zoological Gardens, 51, 81

Longevity, in animal kingdom, 47 _et seq._ human, 84 _et seq._ rules for, 141 in sexes, 44 theories of, 39

Lorand, Dr., on ductless glands, 32

Love, Goethe and, 272

Luxury, 321

Macfadyen, Nencki and Mde. Sieber, on digestion, 153, 161

Macrophags, 25, 147

Mailaender, 235, 255

Malaquin, M., on _Monstrilla_, 116, 117

Male rotifers, death of, 114, 115

Malthus, theory of, 214

Mammals, longevity of, 53

Mammary glands, in males, 186

Man, compared with apes, 184, 185 natural death of, 119 _et seq._ longevity of, 84 _et seq._

Manouélian, M., on neuronophagy, 21, 22

Marinesco, M., on neuronophogs, 19

Marrow of the bones, in old age, 37

_Marsiliaceæ_, duration of life of prothallus, 99

Martin, on Gibbons, 192

Massart, on cause of death in plants, 102, 109

Massol, Prof., 178

Mastication, and intestinal putrefaction, 160

Matchinsky, M., on atrophy of ovary, 26

Maternal instinct, 319, 320

Mauclaire, M., operations on large intestine, 153, 154, 155

Maumus, M., on digestion in cæca, 61

Mauritius, giant tortoise from, 12

Maupas, M., on infusoria, 13

Maya, 178

Mayers, on Chinese elixir, 138

Meconium, appearance of microbes in, 161

Medical selection, 134

Mesnet and Mottet, Drs., cases of hysteria, 203

Mice, duration of life, 41, 43, 56

Michaelis, on muscles of monkeys, 185

Microbes, as cause of senility, 73 in food, 162, 163 passage through intestinal walls, 71

_Middlemarch_, G. Eliot’s, 322

Milk, importance of boiling, 177, 178 microbes of disease in, 177 putrefaction and fermentation of, 167 use of soured milk, 181, 182

Mill, J. S., 323

Milne-Edwards, H., on laws of duration of life, 42

Minot, Prof., on cause of old age, 16

Moa, 213

Moebius, on Goethe, 271 on Schopenhauer, 255

Molluscs, ages of, 48

Mongols, hair in old, 17

Monkeys, longevity of, 83

Monsters, double, 216

_Monstrilla_, life-history of, 115, 116, 117

Montefiore, Sir M., 91

Morality, Christian, 321 definitions of, 303 Kantian, 309, 310, 311, 312 science and, 301 _et seq._

Mortality rates of old persons, 142, 143

Moses, use of soured milk, 171

Mosso, on fear, 194, 196

Muscles, degeneration of, 9, 26, 27

Myxomycetes, 215

Naegeli, on age of trees, 99

Nails, growth of, in the old, 18

Naphthaline, as an intestinal antiseptic, 156

Nature, human, 325

Nausenne, Mde., cause of longevity, 141

Negroes, longevity of, 88

Neisser, Prof., on protection against syphilis, 146

Nematodes, death of, 111

_Nemertines_, life-history of _Pilidium_ of, 109 _et seq._

Nencki and Sieber, on digestion, 153, 161, 169

Neuronophags, 19, 20, 21, 22, 23, 24

Nicotine, use of in experimental production of atheroma, 32

Nietzsche, criticism of Socialism, 230

Nogueira, M., on use of soured milk in Africa, 172, 174

Obstacles, sense of, 258

Old age, Goethe and, 279 _et seq._

Olympian, Goethe as an, 269

Optimism, foundation of, 256 Goethe’s transformation to, 269, 270 _et seq._

Orang-outan, 185, 193

Orotava, dragon-tree of, 96

Orstein, Dr., on centenarians in Greece, 90

Orthobiosis, 212, 325 _et seq._

Ossetes, use of soured milk, 173

Osteoclasts, 30

Ostrich, defecation of, 76

Oustalet, M., on longevity of vertebrates, 46

Ovary, atrophy of, 26

Owls, intestinal flora of, 83

Ownership, collective, 229, 230

Parodi, on old age, 332

Parr, Thomas, 87

Parrots, duration of life, 41 scanty intestinal flora of, 79

Pasquier, Dr. du, on constipation, 67

Pasteur, discovery of lactic microbe, 105, 167

Paulsen, criticism of Kant, 314

Pensions, old age, 3, 4, 133

Pessimism, 129, 233, 234, 239, 241, 249, 266

Pessimist, study of life-history of a, 249 _et seq._

Pflüger, on longevity, 93

Phagocytes, 18, 19

Phagocytosis, examples of, 25, 37

Phalansteries, 229

_Pilidium_, 109 _et seq._

Pitres, M., hysteric patients of, 200

Plague, 323

Plants, death of, 99, 103

Plasmodia, of Myxomycetes, 215, 216

_Pleurotrocha haffkini_, 112, 113

Pochon, Dr., experiments on use of lactic bacilli, 169

Poehl, Dr., on spermine, 139, 140

Pohl, Dr., on growth of hair, 17, 18

_Ponogenes_, as cause of sleep, 120

Potatoes, improved by Burbank, 326

Poushkin, 236

Predestination, and plants, 103

Preyer, Dr., on _Ponogenes_, 120

Prichard, on longevity of negroes, 88

Productivity compared with fecundity, 57, 58

Prostokwacha, 172, 176

Prolongation of life, 132 _et seq._

Prothalli, life of, 99

Psychids, death of, 117

Ptolemy, fear of Hegesias’ philosophy, 235

Punishment, capital, 305

Purgatives, use of, in intestinal putrefaction, 157

Putrefaction, intestinal, 151 _et seq._, 161, 163, 164

Quételet, on stature of the aged, 9

Rabbit, fecundity of, 58

Ravens, absence of putrefaction in intestines of, 75

Reagents, action of, in distorting tissues, 20

Renouvier, C., on his own death, 127

Reproduction, organs of, rudiments in, 189

Reptiles, longevity of, 50

Rhea, cæca of, 60, 77

Rhinoceros, longevity of, 54

_Rhytina_, 213

Riley, James, on food of Arabs, 174

Rimpau, on cultivation of rye, 326, 328

Rist and Khoury, on milk, 178

Rist, M., on ferment of Egyptian milk, 105

Rivière, M., on defecation in ostriches, 76, 78, 79

Robineau, Mde., 5, 6, 7, 8, 128, 159

“_Roman Elegies_,” Goethe’s, 268, 273

Rotifera, duration of life, 39 death of, 112

Roux, anti-syphilitic ointment, 146

Rovighi, on Kephir, 173

Rudimentary organs, 185 _et seq._

Rye, duration of life of, 100 Rimpau’s improvement of, 326

Salpétrière, hysterical patients at, 201 old women in the, 4, 5

Sand, M., on senile brain, 20

Sargent, on age of Sequoia, 98

Sauer-kraut, 165, 171

Sauvage, M., on atheroma, 30

Savage, on character of anthropoids, 193

Saxe-Weimar, Grand Duke of, and Goethe, 274

Schaudinn, spirillum of syphilis, 31

Schiller, Goethe on, 271

Schiller, on moral conduct, 310

Schlanstedt, rye of, 326

Schmidt, on microbes in constipation, 70

Schopenhauer, 235, 247, 255, 277, 330

Schumann, a degenerate, 134

Science, and morality, 301 _et seq._

Sclerosis, in the aged, 31

Sea-anemones, longevity of, 47, 48

Sea-cow, 213

Selection, medical, 134

Seneca, 132, 235

Senescence, Brown-Séquard’s specific against, 139 mechanism of, 25 phagocytosis as cause of, 35

Senility, characters of, 8, 14 and digestive system, 59 theories of causation of, 15 _et seq._

Sensation, analysis of, with regard to pain and pleasure, 243

Sense of life, 26 of obstacles, 258

Sense, organs of, rudimentary structures in, 186, 187

“Sermon on the Mount,” 321

Serums, cytotoxic, 147, 148, 149

Servants, care of, 321

Sex, and longevity, 57

Sexuality, Goethe and, 273 _et seq._ and old age, 276 moral problems of, 305

Sexual organs, abnormalities of, 224

Sexual power and genius, 272

Shakespeare, quotations, 239, 307

Sheep, digestion of, 74 longevity, 55

Sight, rudimentary organs of, 189

Silos, 165

Siphonophora, 217

Skeleton, atrophy of, in the aged, 29

Sleep, and anæmia of brain, 122 and auto-intoxication, 120 and death compared, 125

Sleepiness, compared with hunger, 125

Sleeping-sickness, 124

Small-pox, and mortality rates, 144

Smell, analysis of, 243

Smell, rudimentary organs of sense of, 187

Smoking and longevity, 93

Social animals, 214, 220 _et seq._

Socialism, 228, 229

Society _v._ the individual, 223 _et seq._

Society, and morality, 306

Sociology, dependent on biology, 231

Sollier, Dr., on sensations at death, 130

Solomon, quotation from “Ecclesiastes,” 233

Somnambulism, analysis of, 200 _et seq._

Sorbose, fermentation of, 106

Soured milk, use of, 171, 181, 182

Sparrow, fecundity of, 58

Spencer, Herbert, criticism of Kant, 310 criticism of socialism, 230 theory of morality, 316, 322, 324, 327

Spermatozoa, in old age, 35

Spermine, 139, 140

Stadelmann, on lactic acid in diabetes, 170

Statistics on suicide, 3

Stature, in old age, 8, 9

Stein, Mde. von, 267, 268, 273

Steller’s sea-cow, 213

Stern, M., on disinfection of intestine, 156

Stohmann, on digestion in sheep, 74

Stoics, 309

Stragesco, Dr., on digestion in mammals, 63

Strasburger, on disinfection of intestine, 156, 157 on microbes in constipation, 70

Suicide, 3, 4, 237, 238, 265, 311

Sully-Prudhomme, definition of morality, 303

Suprarenal capsules, and atheroma, 32

Swimming, instinctive power of, 197, 198, 207

Syphilis, 31, 37, 145, 146, 302, 304

Switzerland, centenarians rare in, 91

Tanacol, as an intestinal antiseptic, 156

Taoism and immortality, 137, 138

Taste, analysis of, 243

Tavel, M., operations on large intestine, 152 _et seq._

Taylor, Bayard, translation of _Faust_, 285

Termites, 220, 221

Testis, emulsion of, as used by Brown-Séquard, 139 resistance of, to senescence, 35

Thanatology, 131

Theophrastus, 132

Thymol, as an intestinal antiseptic, 157

Thyroid, effects of extirpation of, 32, 33, 34

_Timon of Athens_, quotation from, 307

Tissier, Dr., on _Bacillus bifidus_, 161 on use of lactic microbes, 181

Tissier, and Martelly, on putrid food, 164

Tobacco and longevity, 93

Tokarsky, on natural death, 126

Tolstoi, and death, 94 “Death of Ivan Ilyitch,” 318

Tortoise, 11, 12, 13, 51

Touch, sense of, in the blind, 257

Troubat, M., on instinctive swimming, 198

Trees, age and death of, 96, 97, 98

_Trypanosoma_, 124

Unicellular organisms, death of, 95

Urine, analysis of, in a centenarian, 7

Utilitarianism, 305

Vacherot, criticism of Kant, 313

Varenetz, 172

Vascular glands, relation to old age, 33, 34

Verworn, Max, on death in infusoria, 95

Vinegar, in preservation of food, 165

Vivisection, 301

Voisin, M., criticism of neuronophagy, 20

Voltaire, 92, 235

Volz, on swimming power of gibbons, 198

Wales, Mr., quotation from Riley, 174

Weber, Dr., on regimen for old age, 140, 141

Weichardt, on cause of fatigue, 122, 123

Weinberg, Dr., on preparation of human serums, 150 on thyroid gland in aged, 33

Weiske, on digestion in sheep, 78

Weismann, A., on cause of old age, 15, 16 on death in infusoria, 95 on duration of life, 41, 43, 45, 51

“Weltschmerz,” in German poetry, 236

_Werther_, Goethe’s, 263, 267

Westergaard, statistics of mortality, 142, 144

Wiedersheim, on intestinal tract, 60

Wine, Goethe and, 271, 279

Wolff, J. H., Goethe’s friend, 271

Women, education, 224 _et seq._

Yahourth, use in intestinal putrefaction, 168, 170, 175, 177, 178

Yeast, conditions of growth, 106

Zeigan, Dr., on adrenaline, 122

Zell, Dr., on blind persons, 259

Zelter, Goethe’s friend, 265

Zola, “La Joie de Vivre,” 248

Zoological Gardens of London, 51, 81

Zortay, Pierre, age of, 87

End of Project Gutenberg's The Prolongation of Life, by Elie Metchnikoff