It has been an theory used, as an excuse, to kill other human beings for years.
My FIL, of all people, fought in Britain in WW2 against the Nazis. We were having a drink at the pub and some conversation. He thought that the disabled needed to be euthanized at birth. My mouth almost flew open. I said to him....”Hitler thought the same thing.” He clammed up.
I couldn’t believe what I was hearing.
It has also been used as an excuse for freedom, as one of its earliest champions and coiner of the phrase “survival of the fittest,” Herbert Spencer, was a libertarian. It has been used more by statists, though, as three of the four types of “social Darwinists” were eugenicists, bellicose nationalists, and progressives (the fourth being lassez-faireists), obviously with overlap between categories.
Are you referring to, ‘survival of the fittest’?