This chapter introduces the volume and contextualises its scope, which covers communicative aspects of the current COVID-19 pandemic as well as the epidemic of misinformation from the perspective of argumentation theory. Argumentation theory is uniquely placed to understand and account for the challenges of public reason as expressed through argumentative discourse. The book thus focuses on the extent to which the forms, norms and functions of public argumentation have changed in the face of the COVID-19 pandemic. This question is investigated along descriptive, normative and prescriptive research lines at the core of the COST Action project CA 17132: European network for Argumentation and Public PoLicY analysis (APPLY). Contributions are divided into three groups, which (i) examine various features and aspects of public and institutional discourse about the COVID-19 pandemic, (ii) scrutinise the way health policies have been discussed, debated, attacked and defended in the public sphere, and (iii) consider a range of measures meant to improve the quality of public discourse, and public deliberation in particular, in such a way that concrete proposals for argumentative literacy are brought to light.