This book originates from a basic, yet innovative question: in which forms of qualification and justification do social actors support themselves to engage in common actions? This inquiry brings to the field of sociological and anthropological analysis the need to take into account socially accepted forms of qualifications of common action and the ways by which they are brought to social situations, and, simultaneously, the need to understand the processes of elaboration of justifications which may demonstrate to social actors that acting in common is worthwhile. As such, this volume analyses the processes by which social actors qualify and communalize certain aspects of their life and also produce justifications that give sense to the ways and means of actions thus brought to the stage of social life. The book will appeal to the wider academic public, namely scholars and post-graduate students, in the areas of sociology and anthropology, and, furthermore, to all professionals in the field of social sciences, throughout the world. In addition, given its treatment of these domains, the volume will also be of interest to professionals in areas such as health, education, and urban planning.