Ethics’ reputation for wide-ranging, interminable disagreement, coupled with conciliationism regarding disagreement, has been leveraged as a basis for moral skepticism. The focus of this essay is on this challenge as it has been applied to philosophical ethics. I call the empirical conjecture underwriting the challenge into question – namely, that disagreement is widespread and roughly balanced within ethics – by describing the results of two studies involving over 400 moral philosophers. The studies reveal widespread agreement, and even consensus, on a range of purportedly contentious moral issues – capital punishment, abortion, eating meat, physician-assisted dying, euthanasia, and many others. The evidence the studies provide suggest that the extent of disagreement within ethics that the conciliationist challenge relies upon likely does not exist.

Moral disagreement is sometimes thought to pose problems for moral realism because it shows that we cannot achieve knowledge of the moral facts the realists posit. In particular, it is ‘fundamental’ moral disagreement—that is, disagreement that is not due to distorting factors such as ignorance of relevant nonmoral facts, bad reasoning skills, or the like—that is supposed to generate skeptical implications. In this paper, we show that this version of the disagreement challenge is flawed as it stands. The reason is that the epistemic assumptions it requires are incompatible with the possibility of fundamental disagreement. However, we also present an alternative reconstruction of the challenge that avoids the problem. The challenge we present crucially invokes the principle that knowledge requires ‘adherence’. While that requirement is usually not discussed in this context, we argue that it provides a promising explanation of why disagreement sometimes leads to skepticism.

Regard for Reason in the Moral Mind argues that a careful examination of the scientific literature reveals a foundational role for reasoning in moral thought and action. Grounding moral psychology in reason then paves the way for a defense of moral knowledge and virtue against a variety of empirical challenges, such as debunking arguments and situationist critiques. The book attempts to provide a corrective to current trends in moral psychology, which celebrate emotion over reason and generate pessimism about the psychological mechanisms underlying commonsense morality. Ultimately, there is rationality in ethics not just despite but in virtue of the neurobiological and evolutionary materials that shape moral cognition and motivation.