ABSTRACT A number of authors have recently advanced a ‘disjunctivist’ view of the rationalising explanation of action, on which rationalisations of the form ‘S A’d because p’ are explanations of a fundamentally different kind from rationalisations of the form ‘S A’d because she believed that p’. Less attempt has been made to explicitly articulate the case against this view. This paper seeks to remedy that situation. I develop a detailed version of what I take to be the basic argument against disjunctivism, drawing on a framework of explanatory proportionality. The disjunctivist cannot reject this framework, I argue, because they need it to respond to another challenge, from psychological individualism. As I explain, however, the proportionality-based challenge is not in principle insurmountable, and I outline a number of ways in which a case for disjunctivism might be developed in response to it. The paper thus clarifies the dialectic around disjunctivism about the rationalisation of action and, specifically, what advocates of the view must do in order to make a compelling case for it.