The introduction presents the reader with the conventional history of the Pioneer Health Centre in Peckham as a space where doctors discovered people’s inherent capacity for responsibility and health. It points to the political uses of this narrative, also scrutinizing interpretations put forward by architectural historians, which regard the centre as a scientific laboratory for the development of new types of “governmentality”. After revealing inconsistencies in these stories the introduction argues that these can only be corrected by looking closely at the archival sources that the book builds on (which are also introduced in this chapter). On this basis, a new interpretation of the experiment as a social knowledge generator is proposed: “Peckham” was a space in which a number of people from very different backgrounds were involved in establishing new knowledge on the merits of social self-organization for creating “health”. Subsequently, a short overview of the chapters of the book is given.