The article offers a succinct conceptual and analytical framework for approaching the ‘great rule of law debate’ currently unfolding in the EU (European Union) and the contending positions of the various EU institutions embroiled in it. It addresses the challenge of conceptualization imbued in the notion of the rule of law, and critically examines the definition of the concept provided by the EC (European Commission). It then demonstrates that over the course of modern European integration, the rule of law emerged as a central dimension in four distinct core areas of EC/EU identity and activity. Should the contemporary crisis of foundational values persist or deepen, each of the four is expected to be adversely affected. Finally, the article explores the emerging ‘rule of law turn’ in the EU.