The doctrine of human dignity says that humans merit a level of moral concern wholly different from that accorded to mere animals; for this to be true, there would have to be some big, morally significant difference between them. Therefore, any adequate defense of human dignity would require some conception of human beings as radically different from other animals. But that is precisely what evolutionary theory calls into question. It makes us suspicious of any doctrine that sees large gaps of any sort between humans and all other creatures. This being so, a Darwinian may conclude that a successful defense of human dignity is most unlikely.

Created from Animals (1990), p. 172