The categories of productive and unproductive labour have been a source of contention among Marxist scholars since Marx first committed them to paper. This article will offer a critique of both the orthodox and autonomist approaches to this issue, arguing that they constitute transhistorical and analytically inadequate interpretations. In contrast, a social form approach to productive and unproductive labour provides a substantive definition of these categories in relation to the commodity form, and brings class struggle back to the forefront in a theoretically consistent manner.