This paper addresses the question of what a concept is and how concepts are relevant to the work of feminist politics. It argues, using the work of Deleuze and Guattari, that the creation of concepts is the production of an event that addresses the unpredictability of events. A concept provides an event with an incorporeal lining, a virtual force that enables the event to give way to new and unpredictable effects. Feminist theory has produced a profound concept that has not yet been adequately understood: the concept of sexual difference, which has been elaborated in most detail in the writings of Luce Irigaray. This article explores how the concept of sexual difference, while addressing the event of the emergence of humanity in two distinct forms, produces the possibility of a new kind of politics and new kinds of social relations that do not reduce sexual difference to its patriarchal expressions.