Of course, Darwin's most important theory was the theory of evolution through natural selection. This theory argued that organisms change and new species emerge because various traits that pop up in animals randomly are more adapted to the animals environment and help it succeed better in living and breeding.
Spencer took Darwin's theories and applied them to sociological situations. He argued that human life consists of competition to survive and he argued that it is the "fittest" who prosper. This helped lead to the idea of Social Darwinism. This says that the wealthy get wealthy because they are simply better than the poor. This means that we should have unlimited competition between people so the best people can rise and the worst fall.
Charles Darwin (1809-1882),is best known for his theories on evolution. which states that all species of plants and animals had evolved (developed gradually) from a few common ancestors.
Darwin's theories asserts that of species evolution had occurred, leading to gradual change taking place over thousands or millions of years. The primary mechanism for evolution was a process called natural selection. Darwin asserted that the millions of species present on earth developed from a single original life form.
Herbert Spencer (1820-1903), was philosopher who attempted to work out a comprehensive philosophy based on the scientific discoveries. He applied his own and Darwin's idea of evolution to biology, psychology, sociology, and other fields.
In biology, Spencer traced the development of life from its lowest recognizable form up to human beings and propounded out with a law of nature that constant action of natural forces tend to change all forms from the simple to the complex. He believed that the human mind developed in this way, from the simple automatic responses of lower animals to the reasoning processes of human beings.
Spencer also first propounded the theory of Social Darwinism based on theory of evolution. This theory states that individuals or groups must compete with one another to survive, and the principles of natural selection favour the survival of the fittest members of society. Such individuals or groups adapt successfully to the social environment, while those that are unfit fail to do so. The social implication of this theory is that differences in economic and political conditions of social classes is because of their capabilities rather than aberrations in the social system.