sentences:  Pius VI made him secretary of the Index (1779) and afterwards Master of the Sacred Palace, and frequently availed himself of his advice and of his pen.Mamachi's great work was to have been his "Christian Antiquities", but his labours in the field of dogma and jurisprudence absorbed so much of his time that he published only four of the twenty books that he planned.Moreover, he lived in an age when the good method inaugurated by Antonio Bosio had been abandoned and, considered as an archaeological work, the synthesis which he had projected is valueless.