The Argument from Expressivism

Metaethical expressivism is a powerful and popular theory of the nature of moral statements. However, the theory entails that there are no moral facts. This is surprising on theism, since on that view, there are moral facts, and God has moral attributes that seem to entail the existence of moral facts about his/her nature. By contrast, the non-existence of moral facts isn't surprising on naturalism, since it seems to make no predictions about the existence of moral facts. Therefore, those who accept metaethical expressivism thereby have at least some grounds for naturalism vis-a-vis theism.