Complex sentence: Calasanz brought the same understanding and sympathy that he had shown to Galileo to his friendship with the great philosopher Tommaso Campanella (1558--1639), one of the most profound and fertile minds of his time, producing famous philosophical works.
Split into simpler sentences: Calasanz brought the same understanding and sympathy he had shown to Galileo to his friendship with the great philosopher Tommaso Campanella (1558--1639). Campanella was one of the most profound and fertile minds of his time, producing famous philosophical works.