Since the Council of Trent the history of the Mass is hardly anything but the composition and approval of new Masses. The scheme and all the fundamental parts remain the same. No one has thought of touching the venerable liturgy of the Roman Mass, except by adding to it new propers.

His final assessment of the Missal of St. Pius V merits careful meditation:

There are many days still on which we say the Mass that has been said for centuries back to the days of the Gelasian and Leonine books. And when they do come, the new Masses only affect the Proper. Our Canon is untouched, and all the scheme of the Mass. Our Missal is still that of Pius V We may be very thankful that his Commission was so scrupulous to keep or restore the old Roman tradition. Essentially the Missal of Pius V. is the Gregorian Sacramentary; that again is formed from the Gelasian book, which depends on the Leonine collection. We find the prayers of our Canon in the treatise De Sacramentis and allusions to it in the IVth century. So our Mass goes back, without essential change, to the age when it first developed out of the oldest liturgy of all. It is still redolent of that liturgy, of the days when Caesar ruled the world and thought he could stamp out the faith of Christ, when our fathers met together before dawn and sang a hymn to Christ as to a God. The final result of our enquiry is that, in spite of unsolved problems, in spite of later changes there is not in Christendom another rite so venerable as ours.

Msgr. Klaus Gamber, one of the greatest liturgists of this century, asks in his book, The Reform of the Roman Liturgy, a very pertinent question concerning the motivation of the reform which followed Vatican II, but was in no way mandated by the Council:

Was all this really done because of a pastoral concern about the souls of the faithful, or did it not rather represent a radical breach with the traditional rite, to prevent the further use of traditional liturgical texts and thus make the celebration of the "Tridentine Mass" impossible - because it no longer reflected the new spirit moving through the Church?

Thanks be to God, the Tridentine Mass is not simply "the most beautiful thing this side of heaven" but the Mass that will not die. Just as the faithful of Milan refused to allow the Ambrosian Mass to be replaced by the Roman Mass, so the faithful of the Roman Rite have refused to abandon the Mass that is redolent of the liturgy "of the days when Caesar ruled the world and thought he could stamp out the faith of Christ, when our fathers met together before dawn and sang a hymn to Christ as to a God." Its renewed use is spreading throughout the world with every day that passes, and each year m,ore and more younbg priests are ordained who are resolved to celebrate Mass only according to the Missal of St. Pius which is as certain to be the Mass of our children as it was the Mass of our fathers.

O God, who for the overthrowing of the enemies of Thy Church, and for the restoring of the beauty of Thy worship, didst choose blessed Pius as supreme Pontiff: grant that we may so cleave unto Thy service, that overcoming all the snares of our enemies, we may rejoice in Thy eternal peace.