50th Anniversary of Paul VI’s Encyclical Mysterium Fidei

September 3, 1965. Fifty years ago today, right before the last session of the Second Vatican Council, Pope Paul VI promulgated his dogmatically rich encyclical on the mystery of the Holy Eucharist, Mysterium Fidei, unambiguously reaffirming the doctrine of the Council of Trent on transubstantiation and condemning the fashionable errors of the day such as “transfinalization” and “transsignification.”