Not exactly. What I'm saying is that Pius VI has stated that it is impossible for the Church to allow a discipline that is dangerous or harmful. John XXII, regardless if it's the opening statement of his bull or not, said that it was possible.
I'm sorry it took me so long to get back to you.
In both instances, one is best served by a deeper, rather than superficial level of what's being taught. In the case of Pius VI, he is saying that the Church cannot approve of any disciplines which is intrinsically
harmful. If you are doubting whether or not this qualification is just, (i.e., if you think I'm merely adding it ad hoc
), then simply draw your attention to the context:
Denz 1533 is contra the Jansenist/Pistoian belief that the liturgy approved by the Church could abandon the principles
of the liturgy. Denz 1578 is more of the same, condemning the notion that the Spirit of God
(i.e., providential infallibility) would not protect against such a scenario: of the Church's discipline itself
being injurious to souls.
John XXII, on the other hand, with his prefatory remarks, makes it abundantly clear that matters extrinsic
to the discipline established have made the discipline less advisable.
Do you see the difference between a law which is only extrinsically made less advisable and a law which, of its very nature, leads to some error or another? .
If you do not, which pope do you think is right, and why?