Herbert Spencer was a British philosopher, sociologist and psyholgist, prominent liberal political theorist of the nineteenth century in Victorian era.
As a polymath, he contributed to a wide range of subjects, including ethics, religion, economics, politics, philosophy, biology, sociology, and psychology.
Spencer was also responsible for attempting to adapt Darwin's theories to human society, known as social Darwinism. Like Comte, Spencer ordered the sciences, also seeking to include sociology as a science.
He is best known for coining the phrase "survival of the fittest," which he did in Principles of Biology (1864), after reading Charles Darwin's On the Origin of Species.
This term strongly suggests natural selection, yet as Spencer extended evolution into realms of sociology and ethics, he made use of Lamarckism rather than natural selection. Thus, unlike Darwin, for whom evolution was without direction or morality, Spencer, believed evolution to be both progressive and good.
Spencer developed an all-embracing conception of evolution as the progressive development of the physical world, biological organisms, the human mind, and human culture and societies.
Spencer was initially best known for developing and applying evolutionary theory to philosophy, psychology and the study of society — what he called his “synthetic philosophy”.
In 1857 he began to plan a vast system of philosophy, which, after Darwin's publication of the Origin of Species in 1859, turned into a scheme for a synthesis of the whole of scientific knowledge based upon the principles of evolution
His System of Synthetic Philosophy,   in 10  vol. (1855 – 1896), held that the physical, organic, and social realms are interconnected and develop according to identical evolutionary principles, a scheme suggested by the evolution of biological species.
Thus sociocultural evolution as well amounted to, in Spencer's phrase, "the survival of the fittest."
Spencer - the founder of the "organic school" in sociology. Society, from his point of view - is an evolving organism, like a living organism, which is considered in biological science.
He developed concepts of  the social organism, laissez-faire economics, political individualism, and a utilitarian ethic based on hedonism.
Spencer protects such individual rights as the security of person, freedom of movement, freedom of conscience, speech, press, etc. However, despite his liberal views, Spencer was against granting political rights to women.
He published Education in 1861, advocating a child-centred approach and emphasizing the importance of science. He advocating natural development of intelligence, the creation of pleasurable interest, and the importance of science in the curriculum.
By the 1870s he had become the most famous philosopher of the age. His works were widely read during his lifetime, and by 1869 he was able to support himself solely on the profit of books. 
His works were translated into German, Italian, Spanish, French, Russian, Japanese and Chinese, and into many other languages and he was offered honors and awards all over Europe and North America.
During his visit to United States he enjoyed great success. His philosophy that justifies the survival of the fittest and individual rights was congenial to the Americans.
At the heart of Spencer's philosophy is the principle of individualism, clearly outlined in the "Principles of Ethics":
Spencer's Principles of Ethics "Every individual has the freedom to do as he wills as long as he does not infringe upon the equal freedom of any other person".