The Introduction by Gabor Betegh and Voula Tsouna outlines the historical and philosophical objectives of the volume, identifies principal questions and challenges that the authors are invited to address, gives summaries of the individual chapters, and specifies the contribution of the volume to the history of scholarship and to contemporary philosophical thinking about concepts. Especially useful is the survey of the technical or quasi-technical terminology used by the ancient authors in order to talk about concepts and related notions. This terminology is rich and nuanced and, as the editors point out, sorting it out is not merely a lexical matter but an inextricable part of the analysis of substantive philosophical questions.