Clavius’ contributions and limitations to the Gregorian calendar reform and modern science education

Christopher Clavius lived during a transitional period in the history of science, the transition from medieval natural philosophy to modern science in the late Renaissance, when the two periods overlapped each other. He was on the threshold of the Scientific Revolution, which began with the great astronomical discoveries by Copernicus and Galileo and led to a “paradigm shift” across European civilization. Most importantly, the discoveries in astronomy posed a serious challenge to the Church. In the face of these intellectual challenges, Clavius carefully weighed the discoveries. He remained committed to the Ptolemaic geocentric planetary system within the framework of Aristotelian natural philosophy, which reaffirmed the celestial system of an unmoving Earth at the center and the other planets in fixed orbits within a solid crystal sphere. In short, Clavius was not a leading figure of paradigm shift in the Scientific Revolution but a prudent mediator between tradition and innovation, and he was a key figure in the Gregorian calendar reform and a pioneer of modern science education.