La Tabula tabularum de Jean de Murs et les modèles de l’arithmétique médiévale

John of Murs (fl. ca. 1317-1345), while he was a master the Faculty of Arts in Paris in 1321, took upon himself to write a text explaining how to use a multiplication table of two-place sexagesimal numbers. The outcome of the work, although only about 3500 words long, has in fact much more to tell us about medieval arithmetic in an astronomical ­context than we might first expect. The Tabula tabularum presents two particularly interesting features for the historian of mathematics : first, the text is not totally polished so that we can actually follow the different steps of his ­composition and reconstruct John of ­Murs’ train of thought ; second, the author tried, with only partial success, to turn his multiplication table into a universal ­computation tool and thus addressed deep mathematical questions about the nature of numbers and the relationship between arithmetical operations. These two aspects allow us to analyze both the heuristic and creative functions of models in medieval arithmetic.