The Peaceful Co-existence of Rites
Art 1. The Roman Missal promulgated by Paul VI is the ordinary expression of the 'Lex orandi' (Law of prayer) of the Catholic Church of the Latin rite. Nonetheless, the Roman Missal promulgated by St. Pius V and reissued by Bl. John XXIII is to be considered as an extraordinary expression of that same 'Lex orandi,' and must be given due honour for its venerable and ancient usage. These two expressions of the Church's Lex orandi will in no any way lead to a division in the Church's 'Lex credendi' (Law of belief). They are, in fact two usages of the one Roman rite.
Of course, there remains some dispute among traditionalists whether this is really the case. What would Archbishop Lefebvre say if he were still alive today? We can gain some insight into his thinking by recalling what he wrote to Dr. Saventhem on September 17, 1976. The Archbishop explains why he felt he had to reject the New Mass in such harsh terms. For him, the abandonment and practical suppression of the old Mass in favor of a new Mass signaled the attempt to impose a new and substantially different Lex credendi.
The fact is, it was necessary for me to denounce the new rites as “bastard” rites and to say that the new rite of Mass is “the symbol of a new faith, a Modernist faith”; and one of the chief reasons for that was the rigor of the attempt to proscribe the old rites. That rigor can be explained on the hypothesis that the purpose was to drive out of the Church, along with those venerable rites, the doctrines of which they are the expression.
Now, if only the old Mass could recover its “proper place” within the life of the Church it would prove the continuity of the one Lex credendi.
If the proscription of our old rites were lifted, that could be taken as a sign that Rome does not wish to impose on us, by means of a completely altered lex orandi, a new law of faith. And if, thenceforward, those venerable rites recovered, in the lived liturgy of the Church, the rights and honors due to them, that would be striking evidence that the Church called “Conciliar” allows us to profess the same faith, and to draw from the same sacramental sources, as the Church of all time…
The Archbishop then expresses his hope for the peaceful co-existence of the rites where people would be free to adopt one or the other form according to their spiritual needs.
For the universal Church I hope, as you do, for the peaceful co-existence of the pre- and post-conciliar rites. Priests and people could then choose to which “rite family” they would belong. Time would then let us know God’s judgement on their comparative values for truth and for their salutary effect on the Catholic Church and on the whole of Christendom. (Cf. Davies, Apologia Pro Marcel Lefebvre, Vol. 1, pp. 293-294)