Despite being conceived as a 'theory of rational choice', orthodox economics fails to ascribe to human beings the ability to choose in a meaningful sense, something philosophical approaches to economics have long noted and tried to remedy. Tony Lawson's critical realism is one attempt at a remedy. If, following Lawson, one conceives of choice as a 'capacity' of human beings, critical realist analysis suggests a distinction between humans' possession and their exercise of this capacity. If one can sustain this distinction, one should be able to distinguish cases in which agents actually exercise their capacity to choose from those in which they do not. Investigation of this distinction does not, however, lead to the desired distinction between such cases. Consequently, a reformulation of the notion of choice is required. An implication for economic theory - namely, the possibility of conceptualizing 'exploitation' - is discussed.