Spencer was eager in denial that he had been influenced by Comte. Yet there is a certain reminder of Comte in Spencer's monumental endeavour to systematise the whole mass of modern scientific knowledge, under the general title of 'A Synthetic Philosophy.' He would show the unity of the sciences and their common principles or, rather, the one great common principle which they all illustrate, the doctrine of evolution, as this had taken shape since the time of Darwin. Since 1904 we have an autobiography of Herbert Spencer, which, to be sure, seems largely to have been written prior to 1889. The book is interesting, as well in the light which it throws upon the expansion of the sciences and the development of the doctrine of evolution in those years, as in the revelation of the personal traits of the man himself. Concerning these Tolstoi wrote to a friend, apropos of a gift of the book: 'In autobiographies the most important psychological phenomena are often revealed quite independently of the author's will.' Spencer was born in 1820 in Derby, the son of a schoolmaster. He came of Nonconformist ancestry of most marked individuality. His early education was irregular and inadequate. Before he reached the age of seventeen his reading had been immense. He worked with an engineer in the period of the building of the railways in the Midlands. He always retained his interest in inventions. He wrote for the newspapers and magazines and definitely launched upon a literary career. At the age of thirty he published his first book, on _Social Statics_. He made friends among the most notable men and women of his age. So early as 1855 he was the victim of a disease of the heart which never left him. It was on his recovery from his first grave attack that he shaped the plan which henceforth held him, of organising the modern sciences and incorporating them into what he called a synthetic philosophy. There was immense increase in actual knowledge and in the power of his reflection on that knowledge, as the years went by. A generation elapsed between the publication of his _First Principles_ and the conclusion of his more formal literary labours. There is something captivating about a man's life, the energy of which remains so little impaired that he esteems it better to write a new book, covering some untouched portion of his scheme, than to give to an earlier volume the revision which in the light of his matured convictions it may need. His philosophical limitations he never transcended. He does not so naïvely offer a substitute for philosophy as does Comte. But he was no master in philosophy. There is a reflexion of the consciousness of this fact in his agnosticism.