Abstract Summary
During the late fourteenth and early fifteenth centuries, the calculating techniques described by the canons found in the Alfonsine Tables became a topic of general epistemological interest at the University of Paris and other major centers of learning in Latin Europe. Scholars and ecclesiastical administrators, such as Nicole Oresme (d. 1382), Pierre d’Ailly (d. 1420), and Nicholas Cusanus (d. 1464) correlated these iterative and approximating methods of calculation with practical modes of knowing, which they associated with a distinct realm of human experience and political action. Drawing on Aristotelian natural philosophy, these scholars often questioned the reliability of the data established in the tables for being based on conjecture and the particularities of sense perception rather than the exact, invariable principles necessary to establish universally accurate predictions. In this paper, I argue that the early Parisian astronomers who shaped the Alfonsine Tables in the 1320s may have already been aware of these epistemological judgments, and sought to mitigate such criticisms in their canons with recourse to Aristotelian definitions themselves. We see this particularly in the first two propositions of John of Saxony’s 1327 canons, which provided instructions for converting epochs of different nations contained in the tables. In these propositions, John of Saxony cited Aristotle’s treatment of the commensurability of time and physical motion, the infinite divisibility of continua, and the importance of observational experience in order to establish the certainty and convertibility of different epochal radices.
