In this article, we elaborate two distinct ways of criticizing international practices: social critique and pragmatic critique. Our argument is that these two forms of critique are systematically opposed to each other: They are based on opposing epistemic premises, they are motivated by opposing political concerns, and they pursue opposing visions of social progress. Scholars of International Relations (IR) who want to work with the conceptual tools of practice theory are thus confronted with a consequential choice. Understanding the alternatives can help them to be more self-reflexive in their research practices and intervene more forcefully in contemporary political debates. We illustrate these advantages through a discussion of the scholarly debate on the practices of multilateral diplomacy through which the United Nations Security Council authorized a military intervention in Libya in 2011.