Charles Darwin and Herbert Spencer Charles Darwin, a British naturalist, revolutionized biology with his theory of evolution through the process of natural selection. Herbert Spencer was the major philosopher of biological and social evolution. Spencer's work significantly influenced 19th century developments in biology, psychology, sociology and anthropology. While Darwin was influential in the fields of natural history and geology, his theory of evolution created great controversy. He changed the way people thought about the role of humans in the natural world. Although these two men made advancement in the theory of evolution they had con