Cardinal Ratzinger on Liturgy - 3

Missale Romanum

"I was dumbfounded upon hearing about the interdiction of the old Missal, since such a move had never been seen in the entire history of Catholic liturgy. The impression was given that this was all quite normal. The previous Missal had been realized by Pope St. Pius V, in 1570, immediately following the Council of Trent (1545-1563); it was therefore considered normal that, after 400 years and a new Council, a new Pope should therefore also publish a new Missal. However, the historical truth is another matter altogether. Pius V had limited himself to republishing the Roman Missal then in use just as it had always been down through the centuries of history. Also, many of his successors, following his example, had also had the Missal republished, without ever opposing one Missal to another. It has always been a continuing process of historical growth and purification in which, however, essential continuity had never been destroyed. There does not exist, nor has there ever existed, a Missal completely made up by Pius V. There was only a new elaboration ordered by him, constituting merely a phase in a long process of historical growth.

Following the Council of Trent, the new reality was of a quite different nature: the eruption of the Protestant "reform" had occurred especially under the form of liturgical "reforms"...; so much so, in fact, that the limits between that which was still Catholic and that which was no longer so, were often difficult to define. In such a confused state of affairs, resulting from a lack of uniform liturgical norms, together with a liturgical plurality inherited from the Middle Ages, the Pope decided that the Missale Romanum, that is, the liturgical text then in use in Rome, was to be introduced everywhere that there existed a liturgy dating back to less than 200 years previously. The reason for this was that the timeless Roman liturgy was most assuredly Catholic in every sense of the term. Wherever it could be done, the preceding liturgy (i.e., that dating back 200 years or more) was allowed to be maintained since its truly Catholic character could be considered to be absolutely certain."  - Joseph Cardinal Ratzinger, La mia vita, pp. 111, 112.