By Andrea Gagliarducci, CNA/EWTN News - Professor Gilfredo Marengo, of the Pontifical Theological Institute for Studies on Marriage and Family stressed that “Humanae Vitae is an authoritative document of the Catholic Church, and it is part of the Tradition. We are called to welcome it as it is and to apply it with an intelligent pastoral plan.”.. Despite being “the most discussed encyclical in the last 50 years,” there is “no need to update it,” Marengo stressed.