In 1713, the Papal Bull Unigenitus condemned 101 propositions extracted from the Jansenist Pasquier Quesnel's popular, seventeenth-century, French-language Bible commentary, the Réflexions morales. This dissertation argues that Unigenitus and the controversies that followed it transformed the ways in which readers of the controversies read and conceived of what they were doing when they did so. Confronted by all legitimate authorities in the Church and French monarchy, Jansenist polemicists appealed to the public to judge if Unigenitus' condemnation of Jansenism was just. To judge, though, this public needed to be informed. To this end, Jansenist polemicists prescribed new models of reading and provided members of this public with both theological and historical arguments to justify the condemned doctrine. These arguments took a wide variety of forms, including cutting-edge genres, such as periodicals; more traditional ones, such as catechisms and almanacs; and non-textual forms, such as engravings and songs. These messages traveled through both formal and informal channels of the licit and clandestine French book trades. The contents of these texts, their forms, and the modes of production and distribution used to bring them to readers conditioned reading in significant ways, notably, by positioning readers on the side of truth against the arbitrary power of the Church and the French monarchy. The ultimate effect of this campaign was a transformation in reading practices from a reading practice that was primarily meditative, focused on a small corpus of mostly books of piety and aimed at elevating one's thoughts to God through self-reflection, to one that was primarily informative, centered on a wider corpus of texts, especially newspapers and contemporary histories, and aimed at gathering knowledge for judgment and argument in the here and now. In helping to bring about this shift, the Unigenitus controversies contributed, in ways both intended and unintended, to a more general "reading revolution" in eighteenth-century Europe and to the making of the critical spirit of the Age of Enlightenment among readers up and down the social hierarchy.