In arithmetic, the strict monastic rules for silence, which made it necessary, for example, to ask for things at meals by signs,[1079] increased the Roman tendency to finger-computation. How elaborate a system was thus worked out we may see from Bede’s work on the subject.[1080] Great stress was laid on the ‘Computus’, a set of tables for calculating astronomical events and the movable dates of the calendar. It was regarded by Cassiodorus as indispensable for the clergy.[1081] The ‘calculus’ of Victorinus of Aquitaine, who invented a new Paschal calendar about the middle of the fifth century, was frequently used.[1082] The idea of mystical numbers, derived from Pythagoras, led to much fanciful nonsense in the Middle Ages, as we may see from Alcuin’s letter to his pupil Gallicellulus,[1083] in which he compared the numbers mentioned in the Old Testament with those of the New. We have seen that monastic education, where, as at Lérins, the abbot was sympathetic, extended beyond the range of theological or church subjects. The Chronicle of Lérins insists on this,[1084] and its statements are borne out to a certain extent by the inscriptions, which show how strongly Vergil’s influence survived among the Christians. Several times we find on the tombstones: Abstulit atra dies et funere mersit acerbo, and the words ‘Subiectasque videt nubes et sidera caeli’[1085] in an inscription on a Bishop of Arles recall the verse describing the apotheosis of Daphnis. An inscription of Narbonne, belonging, probably, to the fifth century, has the phrase ‘summi rector Olimpi’.[1086] As for the Fathers, they are constantly bursting forth into Vergilian language. Paulinus, in the midst of his tirade against the pagan Muses, in the heat of his appeal to turn to the Christian God, slips into ‘inania murmura miscent’,[1087] and Jerome, while urging Julianus to become a monk, ends with a Vergilian quotation: he must follow the example of the Holy Vera, ‘et sit tibi tanti dux femina facti’.[1088] Thus the Christian writers by their own words prove the folly of the extreme anti-pagan point of view, even when they themselves have held it.