 The two features of international law most commonly invoked by those who call into question its legal character are the absence of a centralized system of enforcement and the role of state consent in the formation of rules of international law. Some legal philosophers, while recognizing that international law possesses some features characteristic of law, dispute its status as a genuine and fully-fledged legal order (e.g., Hart 1961 [2012]). We consider these different strands of arguments on the legal nature of international law in turn.