Hobbes
Explanation:
Personally, I think it a bit unfair to link Hobbes with the views of Herbert Spencer, who put forth the theory that became known as "Social Darwinism." I would cite also an article by Peter Amato in Minerva - An Internet Journal of Philosophy (Vol. 6 2002). But if the choice is between Hobbes and Locke, it's easier to make a "Social Darwinism" comparison or connection with the theories of Hobbes.
Thomas Hobbes published a famous work called Leviathan in 1651. The title "Leviathan" comes from a biblical word for a great and mighty beast. Hobbes believed government is formed by people for the sake of their personal security and stability in society. In Hobbes view, once the people put a king (or other leader in power), then that leader needs to have supreme power (like a great and mighty beast). Hobbes' view of the natural state of human beings without a government held that people are too divided and too volatile as individuals -- everyone looking out for his own interests. So for security and stability, authority and the power of the law needs to be in the hands of a powerful ruler like a king or queen. And so people willingly enter a "social contract" in which they live under a government that provides stability and security for society.
The part of Hobbes that would have a similarity to Social Darwinism is that idea that humans by nature are each looking out for their own interest. "Survival of the fittest" was the term that Herbert Spencer used in applying evolutionary theory to how human beings in society and different human societies function toward one another. In "Progress: Its Law and Its Cause"( 1857), Herbert Spencer wrote: "The advance from the simple to the complex, through a process of successive differentiations ... is seen in the evolution of Humanity, whether contemplated in the civilized individual, or in the aggregation of races; it is seen in the evolution of Society in respect both of its political and economical organization." In his book, Principles of Biology (1864), Spencer stated even more fully the idea of humans being in competition with each other by nature, with the strongest forms surviving. He wrote: "This survival of the fittest, which I have here sought to express in mechanical terms, is that which Mr. Darwin has called 'natural selection', or the preservation of favored races in the struggle for life."
