The author argues that while State consent does contribute to international law’s legitimacy, it does not do so by providing a justification for it. States are not bound to obey international law because they have chosen to submit to its authority. Rather, international law provides them with a reason for action, and indeed they have a moral duty to obey it, if and only if they will do better at realizing justice if they act as the law directs them to act than if they act on their own judgment. As a means for crafting international law, State consent is, according to the author, valuable insofar as it yields international legal norms that satisfy this condition. He argues, that in a few cases, it may also constitute an intrinsically valuable expression of trust in the international political community or an international institution that exercises political authority.