This seminal book develops a new perspective on the debate concerning the Europeanisation of private law. The theory is both realistic, building on existing experience, and normative as it focuses on the future. It outlines 'good' Europeanisation in which legal sources can be used across borders; hence the free movement of legal ideas. At its core, is the analysis of the legal consequences of growing societal uncertainty and increasing use of micro-politics, leading to a situation where the law develops through small narratives rather than according to a coherent master plan. The inevitable rule of law concerns around such a development, have to be addressed by transparent legal reasoning. The author masterfully illustrates how this can be achieved in decision-making across Europe, drawing on arguments which are both substantive and authoritative in nature. He shows how all legal actors, including decision-makers and scholars, are morally responsible for the choices made. This is a fascinating intervention in the field of European private law by one of its leading authorities.