This article examines a frequent assumption of sociological accounts of knowledge: the idea that knowledge acts. The performativity of knowledge claims is here analysed through the prism of ‘sociological excuses’: the idea that sociological explanations can act as ‘excuses’ for otherwise unacceptable behaviour. The article builds on Austin’s distinction between illocutionary and perlocutionary effects to discuss the relationship between sociological explanation, sociological justification and sociological critique. It argues that understanding how (and if) sociological explanations can act requires paying attention to (...) social and political conditions of performativity and their transformation in late liberalism. (shrink)