I know that neither of us are presuppositionalists but I was hoping you wouldn't mind answering a question for me. I've heard presuppositional apologists tell atheists they are importing the Christian worldview to get their moral values and duties. Would there be any reason that a Muslim could not say the same thing? Why would it have to be a Christian worldview the atheist is helping himself to and not an Islamic one?
Hi Larry, thanks for the question! You’re right that I’m no presuppositionalist, but I am sympathetic to some of the basic reasoning. So it might surprise some people who know me to hear that I do think God is a necessary precondition for knowledge, since I think God is a necessary precondition for all else that exists! Specifically, for objective moral values and duties, William Lane Craig essentially uses this same reasoning in his moral argument. He first argues that God grounds objective moral values (without God, they would not be around), and objective moral values do exist, therefore, God exists.
Now we ask if Muslims could do precisely the same thing? If the presuppositionalist is right, then no. We could not grant the presuppositionalist his claim that Christianity is needed to make sense of the world and still grant the Muslim his claim. The presuppositional argument precludes Islam being true. However, this is most likely not what you mean, since your last sentence of the question indicates you’d want some reason that we should prefer Christianity over Islam.
And this is why many, perhaps the vast majority of, popular level presentations of presuppositional apologetics don’t go anywhere. More than once, I’ve read a “refutation” of a world religion that basically read something like: Christianity is true; X world religion is incompatible with Christianity; therefore, X world religion has been refuted, and the article’s author metaphorically walked off triumphantly, like some major intellectual exercise had just taken place.
Now, to be fair, some presuppositionalists will in fact try to offer reasons to think the competing worldview is wrong (say, by pointing out an internal incoherence). But they will rarely, if ever, engage in any reasons why Christianity is preferred. I once watched an entire DVD set on apologetics where it was just assertion after assertion. While I fundamentally agreed with most of the assertions, they just didn’t give anyone any reason to believe it. I could go on and on with criticisms, but I don’t like the so-called “method wars,” so I’ll just sum up my answer: the Muslim would be able to make the same claim unless or until one or both of the following occurred: there were reasons given to support Christianity over Islam; Islam was shown to be false (by internal incoherence or something). But notice even the latter move doesn’t necessitate Christianity’s truth. I hope that at least helps!