“Nihil scio certo, & tamen ob incerta non doceo”

This chapter is devoted to exploring the most radical, yet also theoretically mature, developments of probabilism through the works of two theologians: Antonino Diana and Juan Caramuel y Lobkowitz. Active in the central decades of the seventeenth century, when the rigorist antiprobabilist offensive was picking up steam and gaining a sizable polemical capital, Diana and Caramuel had common theoretical interests, despite their widely different scholarly and personal profiles. Despite a long historiographical and polemical tradition that interprets Diana and Caramuel as the quintessentially casuistical and laxist writers, I argue instead that they articulated the most accomplished versions of probabilism as a proper epistemology and as a way to fully incorporate both uncertainties and novelties into the core intellectual system of an increasingly global Catholicism.