In medieval Benedictine monasteries, the sciences played a fundamental role, despite being subordinate to the study of sacred texts. Arithmetic, geometry and astronomy were used, for example, to calculate the hours of prayer and determine important dates such as Easter. Music marked the most solemn moments of the liturgy. Medicine also occupied an important place. The Rule of St. Benedict, in fact, placed great emphasis on the care of the sick. Montecassino preserves precious books addressing all these disciplines.