Certification programs created by nonstate actors such as the Forest Stewardship Council and Marine Stewardship Council are innovative and potentially highly effective governance initiatives. This article works from the premise that these Councils can be understood as political authorities promulgating law. These Councils, and other actors like them, are generally analyzed from the point of view of governance, which triggers questions about their effectiveness and legitimacy. The approach adopted here shifts the focus to questions of their authority and the validity of the rules, standards, and decision-making processes that they have put in place. The Councils have put in motion elaborate networks of actors, creating interactions among social systems and making possible translations from the medium of one system to another. In this manner, the resources of these social systems are made available to the Councils: truth (science), money (economics), power (politics), legality (law), and so forth. One of the challenges that the Councils now face is to pursue the constitutionalization of these networks in the interest of protecting the autonomy of the range of social systems implicated in them while, at the same time, ensuring that these systems’ resources are available within the network. Particular attention will be devoted to the role of law within the networks constituted by the Councils. The role of law is currently difficult to discern; law tends to be closely bound up with science and politics. The concept of the societal constitution serves to draw attention to the threats to law’s autonomy within these networks and sheds light on the particular, and unique, contributions that law could make.