Disclaimer: I’ve never taken a class on apologetics or read a book on it. I gather what I do by the illative sense and usually grudgingly. I’m saying what I’m saying because I was asked. If you take it as in any way actually representative of anything other than what I personally think, you are probably making a mistake.
To begin with, I think there is something I agree on with presuppositionalists. To be a presuppositionalist is to go acknowledge presuppositions. Before you can reason about something, you have to believe something. Everybody has assumptions, things they take for granted, on the basis of which they proceed. A presuppositionalist looks for these assumptions, and tends to act as if presuppositionalism is the only thing that ever thought of them. Moreover, he believes only his assumptions are right. If we must believe what God reveals in order to be right, and if we do believe what God reveals as the basis of all the rest, then in a way the presuppositionalist is right. If you don’t believe in the right thing, how can you have a sound basis for anything else?
Perhaps this is where the charge of fideism arises. I don’t know. I don’t mind being a fideist, if to be one is to assume a few things. I assume a few things such as the intelligibility of the world, the existence of God and Divine simplicity. And that Plato was right.
The problem is that presuppositionalism posits too stark a distinction between believers and unbelievers. Stress the antithesis is one of their loathsome mottos. There are occasions when it is useful to stress that one has bases for knowing thanks to what God reveals and the other has no such bases, but on the whole those occasions are limited. Presuppositionalism drives that stark contrast into all of life, making all of life the realm of the defense of the faith, exaggerating the importance of apologetics for the sake of personal aggrandizement. You can understand what good zeal that demonstrates, but one has to question the knowledge. It often strikes me as the Cold War approach: if they’re not aligned with us, they’re communists, now we just need a shred of evidence to conclude the investigation.
The assumption is that Christians build from sure foundations, and come up with Christian everything: epistemology, mathematics, apple pie recipes. That is the kind of thing that I have no patience for. What kind of historical awareness does that display? What kind of sense? It explains why the more aware among them are hostile to Classical Christian Education, and want to have separate Christian Schools with Christian Math, Christian Science, Christian commitment to Van Til. As a Christian Humanist, it drives me nuts.
The truth is, you don’t need to know everything to get something right, or none of us would ever get anything right. The inconsistency by which Plato can assume something that is true is not one that will subtly erode all the truth out of what he says. Presuppositionalism acts as if it does, and harbors a condescending attitude toward human learning. It is out to demolish all that is not itself, to show how all the rest are wrong. It exaggerates the noetic effects of sin in order to achieve a noetic Manicheism, so that anybody who is not a Christian, cannot really think—cannot know even a leaf, was what Van Til at one point squealed. In ultimate terms, no unbeliever does understand a leaf, but there is a whole heap of knowing about leaves he can have without being ultimate, and in ultimate terms, what does a leaf matter, for crying out loud?
Even in terms of philosophy. I personally think the noetic effects of sin are like the visual effects of sin. Now we have blind people, poor eyesight, glasses and such. But on the whole, most of us can expect to see fine, and there are corrective measures that can be taken. Same with the noetic effects. The problem is not noetic, it is a problem of the heart: the cordial effects of sin. You won’t catch a presuppositionalist going around saying that, though.
How are the noetic effects of sin exaggerated? Rom 1. Their minds are darkened. It means to the presuppositionalist that unbelievers don’t know. I think Paul is saying they can know and the problem is they won’t put it to proper use. It is talking about knowledge of God, and the perversity of humankind is that we refuse to acknowledge him as such, and this has consequences. But the presuppositionalist takes this to make a blanket statement against all human knowing. Because unbelievers don’t recognize God their epistemology is hosed, their epistemological faculty is derailed and useless, in some versions it seems they’re saying all unbelievers are functionally retarded. It is a totalitarian interpretation of what for me is a matter of the affections and limited to the sphere of religion.
It is a kind of triumphalist apologetic that assumes everybody else is wrong and treats them accordingly. Totalitarian triumphalism that is at heart nitwitted.
What if someone should point out that unbelievers know things? Then, they say, Common Grace. Bah, common grace is about God sending rain on the just and unjust: God provides the conditions for life even though we do not deserve them. He allows humanity to go on rather than condemning us all outright. He does this to demonstrate that our hostility is unreasonable; he is the wronged party and he is still kind. And that is all common grace is about, as I understand it. But for the presuppositionalist common grace is the magic that enters to make the noetic Manicheism seem less starkly defined. It allows him to have his cake and eat it. Did an unbeliever come up with that recipe and the cooking end up good even though they are at enmity with God and inconsistently appropriating what is not theirs? Common grace. Did an unbeliever just say what the presuppositionalist belives? The unbeliever is wrong and common grace. They use common grace to do their movie thing: That is produced by unbelievers, but, whoa, there are Gospel elements in the movie, hints of things only Christians would know like sacrifice: common grace. Their common grace is a way to eliminate all possibility of judgment, because you never know what to hold a human being responsible for. It eliminates the possibility of reasonable evaluation by introducing a magical imponderable element. It’s nitwitted.
Most Christians get through life without examining or having a consistently worked out rationale for everything. Most people live this way. I do not say it is the ideal way to live, but I acknowledge it is the only way any of us on this planet really does live. Anybody who thinks they have a consistently worked out system built from the basic premises of faith and thoroughly developed and lived out is very, very young and conceited. Not even cumulative Christianity has such a thing. They think Van Til pretty much had it. An antidote to presuppositionalism is Christian Humanism, which puts the pin into the balloon of the above notion. The only way to maintain the noetic manicheeism that stresses the antithesis between the thought of an unbeliever and a believer is to have an individually worked out system. Anything else would be, as any cursory historical investigation will show, contaminated by ideas, context, language, all sorts of things. Oh, but common grace.
One of my things against presuppositionalism is that it is based on bad historical method. You can’t account for what they expect or even this stark distinction anywhere in lived experience, not unless you comically exaggerate it so that you get a noetic manicheeism between believers and unbelievers. It is not humane. They essentially posit two humanities (well, doesn’t the Bible? Faugh!). They also treat primary sources (Aquinas, for example—yes, it is ludicrous how the antithesis is stressed) as a way to find an offending argument and demolish it; not wholesome. Van Til even does something in the book I had to read which would not pass for a paper at Westminster. He writes about the history of the Trinity citing no primary sources, relying on Hodge and Bavink for everything that went before them. And then we use it as a text. That does not indict present presuppositionalists, except that they bow before him. But it shows there is something amiss, and it is a real problem of historical method and always has been.
Anyway, it posits too stark a distinction: noetic manicheeism to a totalitarian degree, no prisoners. Can an unbeliever not take things for granted that are right? I think he can. Is this a contradiction? Not one that always matters. Everybody has contradictions, even Chrstian Humanists, and specially presuppositionalists. Why are we holding the contradiction we see in anybody’s eye against him at the first chance? The presuppositionalist is holding the contradiction in his eye against whoever opposes him because he wants to believe that if one is not for him one is against him, and therefore an unbeliever, and because the unbeliever is at enmity with God, all his acts are expressions of hostility, even making the bed. This totalitarian approach (you will notice they like to use the word holistic, they mean totalitarian) is crack-potted. A totalitarian apologetics for nitwits.