“He didn’t apply genetic natural selection to humans because he knew it, a.k.a., eugenics, wouldn’t work due to our social nature.”
Firstly, he didn’t know about genes. He prefigured them, in a way, since his variations in inheritability had to be passed on through some medium or other. But not really.
Secondly, he did so apply natural selection to humans. He assumed, following Malthus, that the same forces shaping the animal kingdom held for humans. Which made him, and to an extent all his followers (especially the stupid, stupid sociobiologists), ignorant of human nature. Not to say evolution isn’t one of the greatest scientific theories of all time. It is. It just doesn’t apply to humans, or certain other species with which humans mess.
No, what he described was genes.
Which made him, and to an extent all his followers (especially the stupid, stupid sociobiologists), ignorant of human nature.
Actually, he wrote about exactly that, how the strong would protect the weak in human society, quite the opposite of pure genetic natural selection where the weak would be killed off or allowed to die. He realized that what makes our societies strong is our cohesion, even our willingness to die for others even if it takes us out of the gene pool. That makes a stronger society than one made of selfish individuals.