Published online by Cambridge University Press: 25 November 2019
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.