 Delfin was one of the main opposers to Savonarola, but still promoted the reform inside the Catholic Church which would lead to the Council of Trento.The letters of Delfin, which number more than 4,000, addressed to different religious of his own and other orders and to various secular dignitaries, contain accounts of contemporary events in his own Order and the Church in general.A collection of his Latin letters was published at Venice in 1524.