There have been changes in the Mass over the centuries, but they were always slow, gradual changes, which truly were for the good of the Church. What is most appalling about the changes Bugnini introduced is the fact that he treated the Mass as though it were just a lump of clay to shape in any way he wished. The worst example of this was the change of the Canon. Tradition and Pope Benedict XIV tell us that Pope St. Gregory the Great was the last of the popes to change the Canon in any way. While there could have been an insignificant word or two added since his time, this is unimportant; what really matters is that there was a tradition of over a thousand years in the Church of keeping the Canon untouched and unchanged. Cardinal Gasquet reaffirms this:
“Our present detailed knowledge of this most sacred part of the Mass goes back certainly 1300 years. And with the exception of one short clause added by St. Gregory it has remained practically unchanged to the present day. This fact, that it has so remained unaltered during thirteen centuries, is the most speaking witness of the veneration with which it has always been regarded and of the scruple which has always been felt at touching so sacred a heritage, coming to us from unknown antiquity.”
Additionally, the Council of Trent stated that the Canon has no error and that it “contains nothing that does not savor strongly of holiness and piety and nothing that does not raise to God the minds of those who offer the Sacrifice.” It is so sacred and perfect that Trent anathematized anyone who would claim that it contains error or would wish to do away with it. With these ideas in mind, the point is clear: the Canon of the Mass is such a holy and perfect thing that to change it in any way whatsoever would demand a very serious reason. And if there are to be any changes, they should be almost imperceptible, as the changes in the Canon over the centuries have been. Even more importantly, any changes must not give rise to doctrinal problems or ambiguity. Unfortunately, these two provisions were not observed in the forming of the New Mass, and there instead resulted unacceptably drastic and consequential changes.