Morality can be adaptive or maladaptive. From this fact come polarizing disputes on the meta-ethical status of moral adaptation. The realist tracking account of morality claims that it is possible to track objective moral truths and that these truths correspond to moral rules that are adaptive. In contrast, evolutionary anti-realism rejects the existence of moral objectivity and thus asserts that adaptive moral rules cannot represent objective moral truths, since those truths do not exist. This article develops a novel evolutionary view of natural law to defend the realist tracking account. It argues that we can identify objective moral truths through cultural group selection and that adaptive moral rules are likely to reflect such truths.

Morally progressive social changes seem to have taken place with the onset of democratic governance, the abolition of slavery, the rise of gender equality, and other developments. This essay attempts to demonstrate that natural and objective moral facts are a plausible cause of some morally progressive social changes. Since this hypothesis is a version of naturalistic moral realism, I call it the Naturalist-Realist Hypothesis (NRH). To support the NRH, I argue that objective moral facts are natural facts pertaining to the impartial promotion of well-being within a population of agents facing a social dilemma. I then describe a mechanism to explain how natural and objective moral facts so construed may cause some morally progressive social changes. I suggest that the NRH is a credible hypothesis because it is compatible with empirical findings from research on the evolution of moral cognition and on the sociology of mass political movements.