In this paper, I analyse a controversy that is taking place within the (relatively young) discipline of International Political Economy (IPE). This very lively controversy was triggered by a paper of Benjamin J. Cohen (2007), which offers us a way of slicing up the field (a dichotomy of American versus British approaches to IPE) as well as a proposal for the future development of IPE as an academic discipline. The many reactions this paper provoked (more than 20 articles in journals up to now), provide us with an exceptionally clear insight into the self-understanding of a discipline, and in particular into issues of (un)desired pluralism, heterodoxy, synthesis, dialogue, mainstream, etc. (see, for instance, Helleiner, 2009; McNamara, 2009; Palan, 2009; Phillips, 2009). The importance for philosophers of social science of undertaking such a case-study is threefold. First, the analysis of the controversy will clarify what social scientists themselves consider as the ideal approach towards the multiplicity of approaches in their field ('schools', theories, models, research programs, …); is it coexistence, some form of interaction, or a synthesis of competing approaches? And, how would they translate that ideal into practice? Second, this case-study helps us to test and further our philosophies of social science, in particular in relation to the issue of scientific pluralism – different understandings of (the ideal of) scientific pluralism can be made explicit in the contributions of participants to the IPE-discussion. These understandings are compared with philosophical accounts of scientific pluralism (cf., e.g., Longino, 2006; Mitchell, 2009; Van Bouwel, 2009a and 2009b). Through this comparison, we evaluate the philosophical accounts and make the IPE-contributions more explicit. Which brings us to the third point; the feedback into the social science. Some contributions to the IPE-controversy might benefit from philosophical explications (as concerns the problems of, for instance, conceptual exclusion, strategic pluralism, hermeneutic injustice, consensus/synthesis, etc.). Thus, the relevance of philosophical accounts for the practice of social science will be demonstrated by showing how they help making the intuitions of IPE-scholars present in their contributions more explicit, improve the self-understanding of the field and enable the elaboration of better legitimations of visions on the future development of the discipline.