Rome asserts that the new mass is a valid and licit mass.
The new mass can be valid, it also cannot be. Depends on the priest, and depends on the canon prayers used. But validity does equal legal.
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Rome has never said the new mass is legal to attend/say. It has only said it legally exists. You might say this is a technicality, but the pharisees ruled the world through technicalities when Christ was alive. And the devil rules the world now through technicalities through his many satanic lawyers.
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It has also said that QP is still in force, which disallows any other missal to be used. Paul VI's law only created a missal; it does not give anyone permission to use it. Ergo, QP supercedes Paul VI's law because QP is specific in its rules, while Paul VI's law is general and non-specific. The law with more clarity always takes precedent.
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Did Quo Primum prohibit the promulgation of new rites?
No, but it prohibits the
use of any new rites, it prohibits any changes to the QP rite, and any pressure/command to use a new rite or an altered QP rite.
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QP orders they all attend authorised missals. It did away with every missal that was under 200 years old, but it allowed Catholics to continue to attend the ancient rites.
Agree. And those rites which were 200 years old at the time of 1500s were very, VERY similar to the Tridentine rite (i.e. Benedictine and Dominican rites are 99% the same, save for the addition of St Benedict and St Dominic in certain prayers and other non-essential rubrics).
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Paul VI clearly authorised the new mass, so it's authorised in the same way the ancient ones are.
Yes, he created a new missal, since QP did not forbid this (technically). No, you cannot use it, because it violates QP. Nowhere in Paul VI's law does he:
1. Order anyone to use/attend the new mass
2. Place a penalty for ignoring the new mass
3. Specifically allow anyone to use this missal.
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All Paul VI's constitution says is: "Here is my new missal, which I am creating by this new law. Here are the changes in the new missal. I wish this law go into effect on the 1st Sunday of Advent." All his law does is create a new missal. The use of it violates QP.