It is most probable that no shade of socialism will be able to solve the problem of social life with a sufficient respect for the maintenance of individual liberty. None the less the progress of human knowledge will inevitably bring about a great levelling of human fortunes. Intellectual culture will lead men to give up many things that are superfluous or even harmful, and that are still thought indispensable by most people. The conceptions that the greatest good fortune consists in the complete evolution of the normal cycle of human life and that this goal can be reached most easily by plain and sober habits will convince men of the folly of much of the luxury that now shortens human existence. Whilst the rich will choose a simpler mode of life and the poor will be able to live better, none the less, private property, acquired or inherited, may be maintained. Evolution must be gradual and much effort and new knowledge is required. Sociology, a new-born science, must learn of biology, her older sister. Biology teaches us that in proportion that the organisation becomes more complex, the consciousness of individuality develops, until a point is reached at which individuality cannot be sacrificed to the community. Amongst low creatures such as _Myxomycetes_ and _Siphonophora_, the individuals disappear wholly or almost wholly in the community; but the sacrifice is small, as in these creatures the consciousness of individuality has not appeared. Social insects are in a stage intermediate between that of the lower animals and man. It is only in man that the individual has definitely acquired consciousness, and for that reason a satisfactory social organisation cannot sacrifice it on pretext of the common good. To this conclusion the study of the social evolution of living beings leads me. It is plain that the study of human individuality is a necessary step in the organisation of the social life of human beings. PART VII PESSIMISM AND OPTIMISM I PREVALENCE OF PESSIMISM Oriental origin of pessimism—Pessimistic poets—Byron—Leopardi—Poushkin—Lermontoff—Pessimism and suicide In the attempt to formulate a pessimistic theory of human nature, we are naturally led to ask why it is that so many famous men have come to a purely pessimistic conception of human life. Pessimism, although it has been most prominent in modern times, is extremely old. Everyone knows the pessimistic wail of Ecclesiastes, written nearly ten centuries before our era: “Vanity of Vanities, all is vanity.” Solomon, the supposed author, states that he “hated life, because the work that is wrought under the sun is grievous unto me, for all is vanity and vexation of spirit” (Eccl. ii., 17).