 The problem with equilibrium solutions is that, as in the stag hunt game, many games have multiple equilibria. The problem then becomes how to select one unique equilibrium from a set of possible ones. The problem is compounded by the controversies over equilibrium refinement concepts (see Harsanyi and Selten 1988). Many refinements have been suggested but, as in bargaining theory, all are controversial to one degree or another. One of the interesting developments in social contract theory spurred by game theorists such as Skyrms and Binmore is the appeal to evolutionary game theory as a way to solve the commensuration and equilibrium selection problem (Vanderschraaf 2005). What cannot be solved by appeal to reason (because there simply is no determinate solution) may be solved by repeated interactions among rational parties. The work of theorists such as Skyrms and Binmore also blurs the line between justification and explanation. Their analyses shed light both on the justificatory problem—what are the characteristics of a cooperative social order that people freely follow?—while also explaining how such orders may come about.