This essay advances several overlapping claims about how to conceptualize fiction within the density of historical time. First, I show that fictionality is entangled with ideologies of disenchantment and secularization. There is a long tradition in the West of both distinguishing and deriving fictionality from categories of bad belief; within the framework of the secularization thesis, possessing fiction—which is to say, having the literary infrastructure for a "willing suspension of disbelief"—becomes the mark of an achieved secular modernity. That history suggests the need to reconsider, in turn, what Catherine Gallagher excludes from her well-known account in "The Rise of Fictionality." The present essay seeks to theorize fictionality otherwise, in a manner that is hermeneutic and comparative. To do so, the second section addresses the archive of medieval literature and advocates for a shift in analytic focus, away from contemporary theorizations of literature and toward literary practice. "Commonplaces" of fictionality—or the shared motifs, genres, and contexts for semantic unearnestness—offer one strategy for doing so. The essay's final section then contends that these arguments are related to an important trend in medieval studies, a trend of arguably anachronistic scholarship on topics like medieval disability and medieval race, which deploys modern constructs in nonmodern archives. On the model of such undertakings, a comparative poetics of fiction stands to pluralize the literary-critical concept by returning it to its volatile interface with language's capacity to depict what is nonactual and the reinventions that result.