Iain M. Banks said this quote
“ That is the way with all of your kind… It is how you are made; you must all strive to claw your way over the backs of your fellow humans during the short time you are permitted in the universe, breeding when you can, so that the strongest strain survive and the weakest die. I would no more blame you for that than I would try to convert some non-sentient carnivore to vegetarianism. You are all on your own side. ”