Stjepan Gradić

Stjepan Gradić (1613 to 1683), also called Stefano Gradi, was a polymath, priest and diplomat from the Republic of Ragusa who spent most of his career in Rome. After early schooling in Ragusa he studied philosophy, theology, law and mathematics in Rome and Bologna, learning mathematics from Bonaventura Cavalieri and Benedetto Castelli. He represented his city at the Holy See, took part in the learned circle around Pope Alexander VII and Queen Christina of Sweden, and from 1682 headed the Vatican Library. In mathematics he wrote on Galileo's paradox of the point and the line, arguing against indivisibles in a treatise printed in his 1680 Dissertationes physico-mathematicae quatuor, and he corresponded with Borelli and Fabri on motion and falling bodies. He also wrote Latin verse on the 1667 Ragusan earthquake and organised relief for the stricken city. Much of his work stayed in manuscript.