 This line of argument is one of the most popular in the contemporary debate. Some have developed Rawls’ somewhat vague idea of a duty to “support and comply with just institutions that exist and apply to us” by drawing on Kant’s political philosophy, whose central idea is that political authority is necessary to give concrete content and shape to moral rights that are otherwise indeterminate in the state of nature (Christiano 2008; Ripstein 2009; Stilz 2009). Others have drawn instead on Locke’s political philosophy, whose central idea is that even if fully determined rights do exist in the state of nature, they cannot be adequately protected without authoritative mechanisms designed to adjudicate and punish their violations (Buchanan 2002; Wellman 2005). On either of these views, we have a natural duty to leave the state of nature and enter civil society in order to be able to live next to each other on peaceful terms, respecting each other’s rights.