The European codification project has rapidly gathered pace since the turn of the century. This monograph considers the codification project in light of a series of broader analytical frameworks - comparative, historical and constitutional - which make modern codification phenomena intelligible. This new reading across fields renders the European codification project (currently being promoted through the Common Frame of Reference and the Optional Sales Law Code proposal) vulnerable to constitutionally-grounded criticism, traceable to normative considerations of private law authority and legitimacy. Arguing that modern codification phenomena are more complex than positivist, socio-legal and historical approaches have suggested over the past two centuries, the book stages a pathbreaking method of analysis of the law-discourse (nomos-centred) which questions at once the reduction of private law to legislation and of law to power and, on this basis, redefines the ways in which to counter law's disintegration and crisis in the context of Europeanisation.