He began his career as a Franciscan preacher, speaking throughout Italy. Though he was convicted to die in Rome for the crime of
heresy or recidivism, he was saved by a Dominican inquisitor, the future
Pope Pius V, who repealed the condemnation when Sixtus recanted and pledged to transfer to the
Dominican Order instead. He is considered one of the two most outstanding Dominican scholars of his generation. He had as a master
Lancelotto Politi, some of whose writings he later publicly criticised. Sixtus apparently destroyed all his remaining manuscripts and writings before his death. Sixtus coined the term
deuterocanonical to describe certain books of the Catholic
Old Testament that had not been accepted as
canonical by Jews and Protestants but which appeared in the
Septuagint, and the definer for the Roman Catholics of the terms
protocanonical and the ancient term
apocryphal. His work
Bibliotheca sancta ex præcipuis Catholicæ Ecclesiæ auctoribus collecta (Venice 1566) treats the sacred writers and their works, the best manner of translating and explaining Holy Writ, and gives a copious list of Biblical
interpreters, in eight books. It was the first of the genre of
encyclopedic teaching repertories of
dogma and Church tradition issued in the wake of the
Council of Trent. == Notes ==