We need new analytical tools to understand the turbulent times in which we live, and identify the directions in which international politics will evolve. This volume discusses how engaging with Emanuel Adler's social theory of cognitive evolution could potentially achieve these objectives. Eminent scholars of International Relations explore various aspects of Adler's theory, evaluating its potential contributions to the study of world orders and IR theory more generally. Each chapter focuses on a different aspect of the social theory of cognitive evolution, such as power, morality, materiality, narratives, and practices, and identifies new theoretical vistas that help break new ground in International Relations. In the concluding chapter, Adler responds, engaging in a rich dialogue with the contributors. This volume will appeal to scholars and advanced students of International Relations theory, especially evolutionary and constructivist approaches.