This book demonstrates that the global community of International Relations scholars during the last 100 years have managed to create a mature and accomplished discipline. The book argues that it should be recognised as such. Seven key concepts structure the book, each concept enabling a critical examination of an important dimension of the discipline that goes beyond conventional categories and delimitations. The essay argues that rather than continue to be stuck in more of the same, it is time to move on and, in this regard, the book offers some tentative suggestions about the way forward. Concerning the discipline’s subject matter the argument is that further debates about widening vs. narrowing are unlikely to generate advances. Instead, we should focus on the guiding research questions and the tentative answer they generate. Likewise, instead of defining the discipline as a social science (for better or worse), we should acknowledge the facts that suggest the discipline has always been straddling the social sciences and the humanities and thus been a human science. The book pays serious attention to variations, not least in terms of the functions theories have across time (history) and space. It also aims at escaping the Zeitgeistian conception of diversity. Instead of regarding the discipline as an abstract discursive structure, we should acknowledge that is was created and reproduced by a community of scholars, increasingly within professional institutions. Finally, rather than go for a bland, unspecified ‘global’ or ‘international’ discipline, we should examine fruitful interactions between ‘local’ and ‘global’.