Teoria e prassi dell’aritmetica medievale in lingua latina nei 'Communia Mathematica' di Ruggero Bacone

Theory and Practice of Medieval Latin Arithmetic in Roger Bacon’s Communia mathematica · In his Communia mathematica (pars i, section iii, chapter 4), Roger Bacon provides a dense description of Medieval Arithmetic and its synchronic and diachronic evolution. He offers, indeed, an interesting insight into the knowledge of the time, showing how the connections between the various disciplines were perceived by the intellectuals. Furthermore, the English philosopher shows how, in the Thirteenth century, the distinction between theory and practice in Mathematical Sciences rests on very different criteria from those we are used to today. According to Bacone, in fact, theoretical Arithmetic represents the fruit of a chronologically very distant age, whose intellectuals were not yet able, at least in his opinion, to provide useful notions to people and their activities. Practical Arithmetic, on the other hand, despite being founded on the same principles on which the theoric one is also based, according to Bacon has the enormous advantage of being concrete, that is, useful in the various areas of human existence : for this reason, it includes a large number of disciplines that are also very different from each other, regardless of their degree of complexity, and is open to welcoming very advanced sciences, such as Algebra.