I read this in the comments:
“I find it odd, if not suspicious, that the single individual left off of this list is the man who termed the phrase, “Social Darwinism”. The reason I find it suspicious is because that man is the “libertarian” “thinker”, Herbert Spencer.”
Interested, I decided to research Spencer, as I too had heard of him as a proponent of social darwinism.
Indeed, it is important, as Wikipedia alleges that “He has been claimed as a precursor by libertarians and anarcho-capitalists. Economist Murray Rothbard called Social Statics "the greatest single work of libertarian political philosophy ever written.”"
Here is what I found:
On Spencer’s ethics:
http://en.wikipedia.org/wiki/Herbert_Spencer#Ethics
It appears that he believed in non-aggression and in private property rights. Seems good to me.
On social darwinism:
http://en.wikipedia.org/wiki/Herbert_Spencer#
"According to Roderick Long, Leonard argues that “Hofstadter is guilty of distorting Spencer’s free market views and smearing them with the taint of racist Darwinian collectivism.”
and
The claim that Spencer was a Social Darwinist might have its origin in a flawed understanding of his support for competition. Whereas in biology the competition of various organisms can result in the death of a species or organism, the kind of competition Spencer advocated is closer to the one used by economists, where competing individuals or firms improve the well being of the rest of society
and
Furthermore, Spencer viewed charity and altruism positively, as he believed in voluntary association and informal care as opposed to using government machinery
While further research is needed, it does appear that Spencer has been unduly blamed for eugenics.
Reading some of Spencer’s political views, they actually seem quite nice, believing in the rejection of the state and instead embracing of a voluntary society.