  Moral realism is the target also of many modern appeals to moral disagreement which are often made by philosophers who instead favor nihilist, relativist, constructivist, non-cognitivist or expressivist views. However, the phenomenon has been ascribed other dialectical roles as well. For example, it has also been invoked in support of realism. Metaethics is furthermore not the only domain in which moral disagreement has received attention. Another is political philosophy. An influential view which is known as “public reason” entails that a government’s use of coercive power is legitimate only if it can be justified to the citizens on the basis of principles that all could reasonably accept. That view provides a different context in which facts about moral disagreement are relevant (see Quong 2018 for an overview and discussion). Nevertheless, this entry is exclusively devoted to its metaethical significance.