While the preponderance of recent literature on David Gauthier's Morals by Agreement has focused on his theory of bargaining,1 Joseph DeMarco calls into question the foundation of Gauthier's project.2 DeMarco argues that Gauthier's project depends on the incorporation of extra‐rational values, thereby undermining his attempt to derive morality from the non‐moral premises of rational choice. On DeMarco's account, there are at least three points where Gauthier depends on extra‐rational values. DeMarco finds the first two of these points problematic because he (...) misunderstands Gauthier's theory of rational choice. The third point is more serious; Gauthier does not offer an apparatus sufficient to respond to DeMarco's charge. To disarm DeMarco's third objection, I shall offer a justification of the rationality of autonomous preference formation. (shrink)