Telesio was the head of the great Southern Italian movement which protested against the accepted authority of abstract reason, and sowed the seeds from which sprang the scientific methods of Tommaso Campanella and Giordano Bruno, of Francis Bacon and René Descartes, with their widely divergent results. He, therefore, abandoned the purely intellectual sphere and proposed an inquiry into the data provided by the senses, from which he held that all true knowledge really comes (his theory of sense perception was essentially a reworking of Aristotle's theory from "De Anima").