My question is actually two parts: firstly (and this was inspired by another topic on this forum), the Holy Office seemed to open the gates so to speak regarding Ecumenism under Pius XII (1949) by allowing certain mixed congresses to be attended (as long as the approval of the Ordinary was obtained), and even common prayer such as the Pater Noster or some other approved Catholic prayer. How does such an allowance jive with the harsher (to say the least) attitude of his immediate predecessor in Mortalium Animos? Secondly, sedeoccupantist traditionalists often quote Dom Paul Nau in justification of their position vis-a-vis the Ordinary Magisterium: “…that of inward assent, not as of faith, but as of prudence, the refusal of which could not escape the mark of temerity, unless the doctrine rejected was an actual novelty or involved a manifest discordance between the pontifical affirmation and the doctrine which had hitherto been taught.” (Dom P.Nau, Pope or Church?, op. cit. p.29) Is he granting that there CAN be a “manifest discordance” between acts of the Ordinary Magisterium, and if so, of what sort?
I didn’t find the right solution from the internet.