[originally posted on 14 October 2004]
The underlying methodological and ideological premises of presuppositionalism cause its proponents to ultimately not be able to comprehend non-presuppositionalist thought. It's the proverbial "fish in water" syndrome. They truly seen unable to "get inside the head" of their Catholic opponents (an ability that is crucial to all dialogue). I've frequently seen people who get too immersed in philosophy and lots of "heavy" thought, who are not able to see the forest for the trees, and who get so wrapped up in a billion particulars that they miss the larger picture.
Presuppositionalism is not designed to interact all that constructively with other ways of approaching things, because, by nature, it holds that one either "gets it" or they do not. It's non-negotiable. This ties in with much of the Reformed mindset. Those of us on the outside of it are fundamentally "lessers" because we are unregenerate or screwed-up by natural theology and so forth. I think it works on several subtle, complex levels in that way.
As with C.S. Lewis' "mere Christianity," important Catholic assumptions are disallowed from the outset. We must give up our belief that God specially guides the Catholic Church and preserves her doctrines infallibly to be able to engage in conversation with Reformed presuppositionalists; to have a place at their lofty "table." That is hardly a dialogue at all, is it? Instead, it is an arrogant denial of the "right" of an opponent to even self-consistently hold a doctrine different from theirs, and a refusal to talk to him on equal terms.
Catholics have to think like Protestants and adopt their own peculiar rule of faith (Church or papal infallibility are not allowed to be held without derision from our Protestant brethren) to be allowed the great privilege of talking to their Protestant overlords and masters. Protestants of this sort (a small minority) thus disrespect our basic assumptions. Imagine that; I am not even allowed to defend the Church and her doctrines, as a Catholic apologist, without getting accused of profound epistemological simple-mindedness and ignorance?!
If God chooses to protect one particular Church body and allow it to preserve the fullness of His apostolic deposit, who can stop Him? Who can say such a thing is impossible? We believe this in faith. The Church Fathers believed it. So Calvin and Reformed thought reject it? So much the worse for them. It just shows their ahistorical tendency once again. But to sit there and state that this belief-system is impossible to consistently be thought and held by Christians is preposterous. The fact remains that it has been held, and by far greater minds than Bahnsen, Calvin, or Van Til. God can choose to make the Church play a large role in the means of grace, just as He chose to allow Mary to play her role in redemption history, and the pope as an office to play its huge part.
Protestants of a certain sort virtually reduce Christianity to philosophy. Catholic understanding of doctrinal beliefs is a matter ultimately of faith, or faith and reason and revelation, not reason alone. We believe certain things in faith, not philosophically. And faith can never be logically reduced to mere reason or logic. That doesn't make it non-rational or irrational, but it does mean that faith transcends reason, while being consistent with it, as far as it can go.
One of these beliefs of ours is the infallibility of the Church, and her special role as divinely-protected guardian of the apostolic deposit, which must not be disagreed with. This is not philosophy; it is faith that God can and will do such a thing. Protestants have plenty of faith as well, which cannot be defended in purely philosophical terms.