Naturalistic fallacy:
But, as that letter to Asa Gray shows, Darwin was not the kind to equate the natural and the good; he saw a wasp’s painfully slow execution of a caterpillar as a product of natural selection yet still thought it was a bad thing. (Letting nature prescribe your values—inferring “ought” from “is”—is so famously fallacious that it has a name: the naturalistic fallacy. Darwin’s friend and loudest defender, Thomas Huxley, argued forcefully, in a lecture that was later published as the book Evolution and Ethics, that nature is too cruel to serve as our moral guide.) [“The Truth about Darwin,” Nonzero Newsletter]
