ABSTRACT
Tobias Adami's exhortation to Tommaso Campanella to reconsider certain aspects of his own cosmology arrived during a period of ferment which had been going on for some time. Campanella's initial interest in Pythagoreanism had given way to his adherence to Telesio's philosophy. Campanella speaks about several kinds of devils, and reports that according to the Abbot Trithemius it is possible to see devils made of air by looking intensely at the sun: but the Abbot is wrong, because in actual fact these are not devils, but sunspots discovered by Galileo. In the course of the process of rethinking, Pythagorean themes, which had aroused Campanella's interest right from his youth, began to re-emerge. The extraordinary discoveries in the skies made by Galileo induced Campanella to rethink some of the principles of his philosophical system, an operation which he undertook with courage and honesty, despite his doubts and perplexities, as he tried to save some of its key aspects while adapting others.
