I think it is appropriate for me to explain something at this point in this thread.
While I do not adhere to the judgments of current sedevacantists, at the same time I do not disrespect their conclusions or their thinking practices, because it seems to me that they are doing a valuable work by their study and product. For, if they had not done these things, the things would not be done, and there would be a vacuum of information in that area. There would be nothing to push against, as it were.
The product of their work, therefore, provides a point of reference that serves a purpose, as it establishes a thing, that fills a void that otherwise would be formless and elusive.
Therefore, I appreciate their diligent efforts, and I am not prone to take up swords to fight with them. I am quite happy to have a reasoned and intellectual discussion.
Isn't that really the hallmark of Catholic works?
This pretty much sums up my position, too. I don't really have a problem with sedevacantists per se, but so many of them are unreasonably combative, as if the vacancy or non-vacancy of Peter's chair were a doctrine of faith.
While I appreciate the amicable tone/tenor of these who would co-exist with sedevacantists, the position itself is no better than agreeing to co-exist with modernists.
Sure, certain saints and theologians have speculated on how and/or when Peter could and would lose the Chair.
Given the speculative nature of the subject matter (i.e., It has never been heard of in the history of the Church that a "Pope" who's reign was universally acknowledged was later determined to have lost the Chair at some point), I find it rash to pounce on these writings and apply them to today's situation.
But for the sake of argument, if I am willing to concede that it were theoretically possible for Peter to lose the Chair (or to have never technically inherited it properly), the previous paragraph would stop me in my tracks from declaring it as fact.
And the biggest problem for me would be that none but a future Pope would have juridical authority to pronounce his predecesser had been a usurper.
And this doesn't even begin to consider all the other problems that arise from a positive affirmation of sedevacantism (e.g., consequences for the visibility of the Church devoid of a heirarchy, save anonymous "lone bishops in the woods", etc).
For all these reasons, the arguments on the sedeplentist side of the fulcrum seem to have the greater weight, even if some perplexities from the recent horrible popes begin to give the speculative works of St. Bellarmine, et al, some practical relevence.
But all that aside, I do not like the tradcuмenical approach to traditionalism, as if we could be in union with those with whom we have such fundamental differences (be they convinced sedevacantists or modernists).
To turn a blind eye to that is the infiltration of ecuмenical philosophy into traditionalism.