Recent transformations in governance show that public decision-making no longer occurs solely through the hierarchical authority of the state but increasingly emerges from interactions among governmental, economic, professional, and civil society actors. Although network governance theory explains this shift from government to governance, it has not adequately clarified how network interactions become legally binding and normatively legitimate public decisions. This article develops a legal-theoretical framework through a critical synthesis of governance theory, social systems theory, and the philosophy of law. Drawing on network governance, Luhmann's social systems theory, Habermas's discourse theory of law, and Teubner's societal constitutionalism, it argues that law functions as an institution that receives, filters, processes, and stabilizes diverse social rationalities and claims as legitimate and binding public norms. The article conceptualizes this role as "Law as the Digestive System of Governance," arguing that law is not merely a regulatory instrument but the institutional reason of governance and a meta-governance mechanism for organizing social complexity. Accordingly, network governance represents not the decline of the legal state but a new stage in its evolution.