Herbert Spencer was a sociologist and laissez-faire capitalist that was involved in the Social Darwinism scene. He was the person who coined the phrase "survival of the fittest" which later was used in newer editions of Darwin's On the Origin of Species.

The term survival of the fittest first appeared in Spencer's The Principles of Biology. Survival of the fittest simply means that those who are best fit to the environment or can adapt best to the environment are more likely to survive and reproduce. This idea was heavily influenced by Darwin's theories of natural selection.