Providing and criticising reasons is indispensable to achieve sound public policy that commands the support of both citizens and stakeholders. This need is now widely acknowledged in the recent literature and key EU documents, which highlight the perils of populist discourse and policies. The European network for Argumentation and Public PoLicY analysis (APPLY) improves the way European citizens understand, evaluate and contribute to public decision-making on such matters of common concern as climate change or energy policies. Addressing this need from a multidisciplinary perspective on argumentation, the APPLY Action identifies gaps between the citizens’, policymakers’ and scholarly experts’ argumentation, and explores ways of treating them. This occurs through coordinated research activities in three main areas: a) empirical: an argumentative analysis of EU policy documents and procedures, the media and citizens’ discourse results in an annotated pan-European database on institutional and citizens’ argumentation; b) normative: a critical study of concepts and methods to measure the quality of arguments in public policies results in a unified theoretical and methodological framework to analyse and evaluate public policy argument; c) prescriptive: the development of tools by which policymakers, citizens and various stakeholders engage in well-informed argumentative discussions. APPLY coordinates such networking activities as workshops, conferences, training schools and short-term scientific missions among European and international scholars and stakeholders. This provides insights into the understanding, evaluation and production of public policy arguments. APPLY thus benefits European policymakers and citizens, but also consolidates a currently dispersed argumentation scholarship across Europe and beyond.