The Evolutionary Challenge to Moral Realism

Abstract

Until relatively recently, philosophers rarely questioned the existence of moral truths. Differences in moral philosophy were focused not on whether moral truths exist—since their existence was usually taken as a given—but rather on what these truths are. Metaethical discussions about whether moral truths exist became more widespread in the twentieth century, thanks in large part to the noncognitivist arguments of philosophers like A. J. Ayer. Following on the heels of the logical positivist movement that was in vogue during the early part of that century, the noncognitivists believed that moral claims held no truth-value. Falling prey to persuasive objections, noncognitivist attacks on moral realism began to fall out of favor toward the latter half of the twentieth century, giving way to more sophisticated antirealist arguments. One of the better known of these was the evolutionary argument put forth by Michael Ruse and E. O. Wilson (19 8 6).1 According to this view, our moral beliefs are the product of natural selection, and their existence is owed to the fact that they served our survival needs by fostering cooperation among our evolutionary ancestors. Following common practice, I use the term “moral nativism” to denote the view that the human moral faculty is innate and owes its existence to its being an evolutionary adaptation that provided fitness advantages to our ancestors.