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