Such a transformation or evolution cannot be regarded as unusual. In _The Nature of Man_, I showed that most of the great pessimistic writers had been young men. Such were Buddha, Byron, Leopardi, Schopenhauer, Hartmann, and Mailaender, and there might be added many other names of less well known men. The question has often been asked why Schopenhauer, who was certainly sincere in his philosophy and who extolled Nirvana as the perfect state, came to have a strong attachment to life, instead of putting it to a premature end as was done later on by Mailaender. The reason was that the philosopher of Frankfort lived long enough to acquire a strong instinct of life. M. Moebius,[184] a well-known authority on madness, has made a close investigation of Schopenhauer’s biography, and has established the fact that towards the end of his life his views were tinged with optimistic colours. On his seventieth anniversary, he took pleasure in the consoling idea of the Hindoo Oupanischad and of Flourens that the span of man’s life might reach a century. As Moebius put it, “Schopenhauer as an old man enjoyed life and was no longer a pessimist” (p. 94). Not long before his death he still hoped to survive yet another twenty years. It is true that Schopenhauer never recanted his early pessimistic writings, but that was probably because he did not fully realise his own mental evolution. In looking through the work of modern psychologists, I cannot find recognition of the cycle of evolution of the human mind. In Kowalevsky’s able and conscientious study of pessimism, I was specially struck by one phrase. “Evils such as hunger, disease, and death are equally terrible at all stages of life and in every rank of society” (p. 95) said that author. I notice here a failure to recognise the modification of the emotions in the course of life which, none the less, is one of the great facts of human nature. Fear of death is by no means equally great at all stages of life. A child is ignorant of death and has no conscious aversion from it. The youth and the young man know that death is a terrible thing, but they have not the horror of it that comes to a mature man in whom the instinct of life has become fully developed. And we see that young men are careless of the laws of hygiene, whilst old men devote to them sedulous attention. This difference is probably a notable cause of pessimism in young men. In his studies of the mind, Moebius[185] has stated his view that pessimism is a phase of youth which is succeeded by a serener spirit. “One may remain a pessimist in theory,” he says, “but actually to be one, it is necessary to be young. As years increase, a man clings more firmly to life.” “When an old man is free from melancholia, he is not a pessimist at heart.” “We cannot yet explain clearly the psychology of the pessimism of the young, but at least we can lay down the proposition that it is a disease of youth” (p. 182).