Several decades ago, Pietro Redondi's Galileo: Heretic famously argued that Galileo was put on trial by the Roman Inquisition for his Copernican worldview only as a diversion to conceal his dangerous atomist teachings that undermined the Catholic dogma of transubstantiation.

At that time, the central archives of the Congregation for the Doctrine of the Faith were not open. Since their opening in the mid-1990s, a vast and still growing body of scholarship has shed new light on the Holy Office and the Congregation of the Index of Prohibited Books. Their functioning, composition, and evolution are now better understood, and crucial aspects of their activities have been scrutinized. A more nuanced appraisal of the Inquisition's action has thus emerged. Scholars now tend to consider them in a web of institutions competing to define orthodoxy and to control society and culture. Censorship is certainly one of the areas of research that has most benefitted from the Roman archives. The effects of censorship on natural philosophy have been the object of numerous studies and editions of archival materials. The elusive nature of orthodoxy and the shifting boundaries between theology and philosophy have also been underscored. Several new studies on Redondi's thesis and post-Cartesian Eucharistic philosophy have seen the light too.

In this chapter, I shall revisit the debates on the Eucharist and atomism as the backdrop of the questions of credibility and authority addressed in this book.