This work investigates the historical and functional mechanisms by which non-legislative texts acquire the status of authoritative legal sources. Nils Jansen, a scholar of legal history and comparative law, examines how private or scholarly codifications—such as the Institutes of Justinian or the Restatements of the American Law Institute—attain binding force within legal systems. He argues that the authority of these texts is not derived from state enactment but from their internal coherence, intellectual prestige, and the consensus of the legal community.

Legal scholars characterize this text as a rigorous contribution to the study of legal sources and the sociology of law. Experts frequently highlight the author's ability to synthesize complex historical data into a coherent framework for understanding how authority is constructed outside of formal legislative channels.