As a sociologist and a theologian, Peter Berger (1929–2017) would not necessarily have been expected to be referenced in this book. However, this chapter aims to show that Berger influenced political science from the outside in several ways. These changes can be characterized as twofold: as a displacement and as a layering. The displacement relates to Berger’s book The Social Construction of Reality (1967), co-authored with Thomas Luckmann, whose impact went beyond what the authors intended and expanded the remit of constructivism in social science. Through a study of co-citation of this work and its graphing with VOSviewer, it is possible to identify the subdisciplines or schools of political science that were most influenced by it. On the other hand, the layering is related to Berger’s work as a sociologist of religion. His work had a deep impact on social science through what has been called the secularization paradigm and the rehabilitation of religion decades later. In political science, the secularization paradigm contributed to marginalizing religion from analysis. Peter Berger’s own shift on this point would contribute to modifying political science perceptions of religion. The chapter is divided into three parts. First, the life and trajectory of Peter Berger are described, with insights into how his personal trajectory probably impacted his sociology. Then, I examine the contribution Berger made to the discipline by reframing both epistemological and ontological questions in social and political science. Finally, the chapter ends with a consideration of Peter Berger’s influence on social and political science through the aforementioned methodology of co-citation analysis.