This paper is concerned with the treatment by Jon Elster of methodological aspects of Marx’s work, and, in particular, with his assessment of Marx’s distinctive contribution to methodology. The relevant material is to be found in a variety of writings with the most complete and systematic presentation in Making Sense of Marx. The issues to be discussed here comprise, of course, only a single dimension of Elster’s view of Marx. It is, however, a strategic one whose influence is felt throughout the whole. Moreover, it is the dimension which is closest to the intellectual interests of Elster himself. Prominent among those interests has been the question of the relevance of methods of formal reasoning, particularly of modal logic and of game theory, to the study of society. Hence, the present emphasis should take one near the heart of Elster’s Marx, and offer a perspective on his thought in general.