http://strobertbellarmine.net/books/Concerning_A_SSPX_Dossier_on_Sedevacantism.pdf

14.  Fr. Boulet then raises and refutes the possibility of a presumption of guilt.

3.7.  Could the pertinacity of John-Paul II be presumed?  Could we make such a statement looking at the insistence of the Pope on the new ways, and this in the face of all tradition and its present-day witnesses?  Perhaps; but not socially, which means, as regards loss of office, etc., which must not be presumed but proven, otherwise societies would collapse.  One can understand that quick and imprudent answer to such difficult question could easily lead someone to sink in the quicksand of Sedevacantism.  If John Paul II often enough makes heretical affirmations or statements that lead to heresy, it cannot easily be shown that he is aware of rejecting any dogma of the Church.  It appears that, in his conduct, John-Paul II is deeply convinced that he is doing his best for the service of the Church.  How is it possible for subjects to prove with moral certainty that the Pope, in his heart of hearts (i.e., within himself), actually hopes and wishes to cause and bring evil upon his subjects and that it is on account of this evil will that he promulgates evil laws?  It is not possible.  As a typical liberal, John-Paul II is multiplying the ambiguous statements, and concessions, in order to please the world.  It may happen that he is making heretical statements without even realizing it:  thus he cannot be found as a formal heretic.  Therefore, as long as there is no sure proof, it is more prudent to refrain from judging.  This was Archbishop Lefebvre's prudent line of conduct.

a) I am sure most traditional Catholics will agree that we may not presume pertinacity, but when something is manifest it does not need to be presumed.  Did John Paul II know that the Church teaches that we are forbidden to do the many, many, things he did, and that we are forbidden to believe in the heretical notions that he was plainly in love with, such as universal salvation?  Well, he was granted a Doctorate in Sacred Theology by the Angelicuм, and the sponsor of his thesis was the famous anti-Modernist Fr. Garrigou-Lagrange.  It is ridiculous to suppose that such a student did not know the basics off the Catholic Faith.  To review the facts is to behold the answer.  

b)  As for quicksand, that is an apt term to describe the anti-sedevacantist arguments presented in this booklet of Fr. Boulet's.  If it were not apparent that he had been deceived by a badly-translated version of a work which already suffered a few defects, one would be tempted to think that the arguments had been constructed from scratch for a pre-determined end, so bad do they appear.

For example, what are we to make of this?  "How is it possible for subjects to prove with moral certainty that the Pope, in his heart of hearts (i.e., within himself), actually hopes and wishes to cause and bring evil upon his subjects and that it is on account of this evil will that he promulgates evil laws?  It is not possible."

Whence the relevance of John Paul II's belief that he is doing good in spreading his ideas?  The question is not what self-deceptions he may have adopted as salves of his conscience, but rather we need to know only two things, viz.  Are his ideas contrary to dogma?  And, does he know that his ideas are contrary to dogma?  The answer can only be yes, to both questions.  But the poverty of the argument can be observed even without noticing its falsity, for Fr. Boulet has in no place prior to this even claimed that we must read someone's heart to identify actual heresy.

But let St. Pius X answer this objection, he who knew the Modernists so well, and fought them so valiantly and successfully.

Although they express their astonishment that We should number them amongst the enemies of the Church, no one will be reasonably surprised that We should do so, if, leaving out of account the internal disposition of the soul, of which God alone is the Judge, he considers their tenets, their manner of speech, and their action.  Nor indeed would he be wrong in regarding them as the most pernicious of all the adversaries of the Church.  For, as We have said, they put into operation their designs for her undoing, not from without but from within.  Hence, the danger is present almost in the very veins and heart of the Church, whose injury is the more certain from the very fact that their knowledge of her is more intimate.  Moreover, they lay the axe not to the branches and shoots, but to the very root, that is, to the faith and its deepest fibres.  And once having struck at this root of immortality, they proceed to diffuse poison through the whole tree, so that there is no part of Catholic truth which they leave untouched, none that they do not strive to corrupt.  Further, none is more skilful, none more astute than they, in the employment of a thousand noxious devices; for they play the double part of rationalist and Catholic, and this so craftily that they easily lead the unwary into error; and as audacity is their chief characteristic, there is no conclusion of any kind from which they shrink or which they do not thrust forward with pertinacity and assurance.  To this must be added the fact, which indeed is well calculated to deceive souls, that they lead a life of the greatest activity, of assiduous and ardent application to every branch of learning, and that they possess, as a rule, a reputation for irreproachable morality.  Finally, there is the fact which is all but fatal to the hope of cure that their very doctrines have given such a bent to their minds, that they disdain all authority and brook no restraint; and relying upon a false conscience, they attempt to ascribe to a love of truth that which is in reality the result of pride and obstinacy. [Pope St. Pius X, Pascendi]  

c)  In principle, certainly all good and sensible Catholics subscribe to Fr. Boulet's comment, "Therefore, as long as there is no sure proof, it is more prudent to refrain from judging.  This was Archbishop Lefebvre's prudent line of conduct."  The question is entirely - or at least it should be - a question of fact.