This article traces the different paths taken by constructivism in International Relations, from its emergence as a critical social theory in the 1980s, in response to the third debate between positivist rationalists and post-positivist reflectivists, to Alexander Wendt's project to seize a middle ground and to bridge the rationalist–reflectivist epistemological gap. The article, then, examines the intra-debates among conventional and critical constructivists on Went's project, as well as the rise of the new constructivism after Wendt left the constructivist research program. The article explores the Wendtian project's epistemological tensions and demonstrates how such tensions led to a plurality within constructivism: modernist conventional and postmodernist critical (reflectivist). It highlights that Wendt's leaving constructivism and his shift to a quantum approach have not caused constructivism to decline, but instead, it continued to thrive through the efforts of a new generation of constructivists. The article argues that three main developments in International Relations over the past twenty years have contributed to its ongoing thriving: the decline of epistemological polarization among IR theories; the rise of critical realism as a philosophy of science in International Relations, and the emergence of analytical eclecticism.
