This essay reexamines the conventional opposition in genre criticism between modern realism and classical tragedy. By adapting Roland Barthes’s account of realist representation with J. L. Austin’s theory of speech-acts, the essay shows that epistemological skepticism animates the conventionality of certain literary techniques in modern realism. This account of the relation between realism and skepticism establishes grounds for further comparison with the seemingly antithetical generic tradition of tragedy. As a means of identifying previously unrecognized affinities between ancient tragedy and modern realism, this essay offers a model for how texts “perform” their genres. The essay describes these literary speech-acts as “genre performatives,” which are smaller-order gestures, devices, and formal techniques that at once present and execute a text’s status as part of any given genre. Formal expressions of epistemic contingency—skepticism’s appearances across a spectrum of literary conventions—function not as abstract philosophy but as mechanisms that shore up the conceptual integrity of a literary text’s wider generic tradition. Instead of imposing a sequence of ruptures in literary history or identifying rigid classes of characteristics that define any given genre, this essay demonstrates that “genre performatives” allow for comparisons across the longue durée (long term) of literary history and across ostensibly unrelated literary texts. The authors under consideration include Euripides, Sophocles, Miguel de Cervantes, William H. Gass, and Gustave Flaubert, among others.