Strands of International Relations scholarship have attempted to develop and theorise the international system from the perspective of the ‘middle powers’ for decades. However, scholars have struggled to agree on the essential dispositional characteristics of this category of actors, stunting theoretical progress. This article advances two arguments. First, I argue the reason for this impasse is that extant scholarship uncritically adopts a ‘category of practice’ as a ‘category of analysis’. Second, drawing on sociological and literary approaches to the rhetoric of the ‘middle class’ in domestic societies, I develop an alternate interpretive approach. I argue that ‘middle powers’ is better understood as a ‘category of practice’, and that one of the term’s main uses is to distinguish certain states that hold no real prospect of achieving great power status but are nevertheless anxious to differentiate themselves from ‘small states’ who occupy the lowest stratum of stratification within the ‘grading of powers’. Following an illustrative case study of Australian and Canadian attempts to establish the ‘middle power’ category in the 1940s, the article then outlines the implications of the argument for how scholars think about stratification and status in world politics.