Here is the basic syllogism of the sedevacantist:
The new liturgy of the Consilium is bad,
but the Church is infallible in her discipline,
therefore, the Pope must be a false claimant.
I concede the major and subdivide the minor. The conclusion is invalid. The minor fails to distinguish between a particular discipline and that which a particular discipline is based. For example, penance is a good discipline which is based upon divine and natural law. Therefore, in the abstract, assigning penance is good in itself, though that does not necessarily imply that an unwise particular penance be admitted, even in a large part of the Church. External and social worship of God in the form of the liturgy is a good discipline and the Church is infallible insofar as she demands this form of worship in public, but that does not necessarily imply that a bad liturgy be tolerated or even de facto promoted by a portion of the hierarchy at a given point in history. It is not even prescribed de jure, for we have official testimony that the old liturgy was never legally abrogated. Therefore the sede errs by excess in promoting an opinion that is not sound. Their opinion of the Papacy is predicated, in part at least, upon another theological opinion. It is precarious, rash and unjust for they are taking away something that belongs in reality to someone else.
On the flipside, here is the syllogism of the neo-conservative:
The Church admits the new liturgy as a legitimate form of worship,
but the Church is infallible in her discipline,
therefore the new liturgy must be good for the Church.
Notice the same minor, but forces a different conclusion?
