The Messianic Drew has a post up where he explains seven reasons, and I’ll add a still more important reason below.

His introduction:

While most Christians will agree that there is a need to defend the faith, many will not realize that there is a debate regarding methodologies. This paper will address the various apologetics methods, and then analyze before critiquing the relatively new method of presuppositionalism. While this method has a lot to offer from a practical apologetics standpoint, it cannot be held rationally as a worldview. This paper will give seven reasons why this is the case. Before addressing presuppositionalism, an introduction to other apologetic methodologies is in order. The main form of apologetics used historically is called Classical Apologetics. Under this method, the apologist gives arguments for the existence of God, and then proceeds to develop Christian evidences for the Christian worldview. Arguments like the moral argument, and other reason-based argumentation tend to dominate this method. If classical apologetics is a two-step method, evidentialism is a one-step method. The evidentialist will usually forego rationalistic argumentation and will simply bring out evidences for the Christian worldview. The method of Gary Habermas is an example of evidentialism. Those methods as well as presuppositionalism are the main methods of apologetics. There are others as well, such as fideism, which tells people to just believe without argument. Polemical apologetics seeks to attack other worldviews. There are cumulative case methods of apologetics, where two worldviews face off for which one better answers life’s deepest questions. There is also eclectic apologetics, which seeks to borrow methods from other schools of apologetics depending on the need. This brings the discussion to presuppositionalism, which seeks to examine the underlying assumptions of any worldview. In short, presuppositionalism states that one’s foundational views are the only truly relevant factor in discussing worldviews. The founder of modern presuppositionalism is Cornelius van Til.

Here are his 7 points:

Presuppositionalism is circular reasoning Presuppositionalism minimizes common grace Presuppositionalism confuses ontological priority with epistemic priority Presuppositionalism presupposes a highly controversial theory of knowledge Presuppositionalism often forgets that Christianity is, at least in principle, falsifiable Van Til’s apologetic might not even be Christian, but may be merely theistic Presuppositionalism faces the problem of incommensurability

And here is #6 in detail:

John Johnson gives a devastating critique as to why Van Til’s system is wholly inadequate when addressing other faiths, such as Islam. Van Til argues from Romans 1:18-21 that non-Christians suppress the truth, and that a presuppositional technique is necessary. However, this section of the Bible deals with knowledge of God, but not theological issues about the Trinity, Jesus, salvation by grace through faith alone, etc. [12] Instead, it only says that unbelievers are without excuse for denying monotheism. Paul reinforces this in Acts 17, when he talks about the statue to an unknown God. Paul deals with the Athenians on their own ground. A more practical example is what I call Artscroll Judaism. This is a fundamentalist sect of Orthodox Judaism, with its own think tanks which can give you an answer to anything. Anyone who is willing to take the leap into the system will find it every bit as coherent as one would find the Reformed Christian view. John Warwick Montgomery gives a fable about a conversation between two presuppositionalists from two different religions: the Shadok religion, and the Gibi religion. Shadok: You will never discover the truth, for instead of subordinating yourself to revelational truth (The Shadok Bible) you sinfully insist on maintaining the autonomy of your fallen intellect. Gibi: Quite the contrary. [He repeats the same assertion substituting the Gibi Bible for the Shadok Bible.] And I say this not on the basis of my sinful ego but because I have been elected by the Gibi God. Shadok: Wrong again! [He repeats the exact same claim, substituting Shadok Election for Gibi Election.] Moreover, the sovereign election of which I am the unworthy recipient has been the very work of God the Shadok Holy Spirit. And all of this is clearly taught in the self-validating Scripture of our people, which, I should not have to reiterate, derives from the true God and not from sinful, alledgedly autonomous man. Gibi: How dare you invert everything. [He laboriously repeats the preceding argument, substituting Gibi election, the Gibi Holy Spirit, and the Gibi Bible.] Shadok: Absurd! This is the inevitable result of your colored glasses. Gibi: It is you who have the glasses cemented to your face. Mine have been transparent through sovereign grace and Gibi election, as proclaimed by the Gibi God’s word. Shadok: Your religion is but the inevitable byproduct of sin—a tragic effort at self-justification through idolatry. Let’s see what the Shadok God really says about his word. Gibi: I will not listen to your alleged “facts.” Unless you start with the truth, you have no business interpreting facts at all. Let me help you by interpreting facts revelationally. Shadok: Of course you will not listen to the proper interpretation of facts. Blinded by your sin, you catch each fact as you would a ball—and then you throw it into a bottomless pit. Gibi: That’s what you do with what I say—a clear proof of your hopeless, pseudo-autonomous condition. May the Gibi God help you. Shadok: May the Shadok God help you![13] As Montgomery notes, this encounter is hopeless, since neither side can appeal to neutral facts to solve the dispute. Both sides are reduced to chest-thumping, loud assertion, and empty fideism.

It’s funny but it’s true! This is presuppositionalism in action. It’s arguing without appealing to any facts.

And here is my eighth point from my post on presuppositionalism.

Excerpt:

My view of presuppositional apologetics is that is as a system, it is circular reasoning. It assumes Christianity in order to prove Christianity. But there is an even worse problem with it. It’s not a Biblical way of doing apologetics. It’s man’s way of doing apologetics, not God’s. I think that the best way to understand Van Til’s apologetics is by saying that it really just a sermon disguised as apologetics. The problem is that Van Til’s sermon has no basis in the Bible. Wherever he is getting his view from, it’s not from the Bible. When I look the Bible, I don’t see any Biblical support for the view that pre-suppositional apologetics is the only approved way of defending the faith. Instead, the standard method seems to be evidentialism. In Romans 1, Paul writes that people can learn about God’s existence from the natural world. Romans 1:18-23: 18The wrath of God is being revealed from heaven against all the godlessness and wickedness of men who suppress the truth by their wickedness, 19since what may be known about God is plain to them, because God has made it plain to them. 20For since the creation of the world God’s invisible qualities—his eternal power and divine nature—have been clearly seen, being understood from what has been made, so that men are without excuse. 21For although they knew God, they neither glorified him as God nor gave thanks to him, but their thinking became futile and their foolish hearts were darkened. 22Although they claimed to be wise, they became fools 23and exchanged the glory of the immortal God for images made to look like mortal man and birds and animals and reptiles. And in Acts, Peter appeals to eyewitness testimony for the resurrection, and Jesus’ miracles. Acts 2:22-24, and 36: 22“Men of Israel, listen to this: Jesus of Nazareth was a man accredited by God to you by miracles, wonders and signs, which God did among you through him, as you yourselves know. 23This man was handed over to you by God’s set purpose and foreknowledge; and you, with the help of wicked men, put him to death by nailing him to the cross. 24But God raised him from the dead, freeing him from the agony of death, because it was impossible for death to keep its hold on him. And finally from the same chapter: 36“Therefore let all Israel be assured of this: God has made this Jesus, whom you crucified, both Lord and Christ.” Professor Clay Jones of Biola University makes the case that the use of evidence when preaching the gospel was standard operating procedure in the early church. (H/T Apologetics 315) Intro: In 1993 I started working for Simon Greenleaf University (now Trinity Law School) which offered an M.A. in Christian apologetics (Craig Hazen was the director). Much of my job was to promote the school and although I had studied Christian apologetics since my sophomore year in high school, I decided I needed to see whether an apologetic witness had strong Biblical precedence. It does. As I poured through the Scripture I found that Jesus and the apostles preached the resurrection of Christ as the sign of the truth of Christianity. What follows are some of the passages which support the resurrection witness. Here is my favorite verse from his massive list list of verses in favor of the evidential approach to Christian apologetics: Mat. 12:39-40: A wicked and adulterous generation asks for a miraculous sign! But none will be given it except the sign of the prophet Jonah. For as Jonah was three days and three nights in the belly of a huge fish, so the Son of Man will be three days and three nights in the heart of the earth. Jesus is saying that the resurrection was deliberately given as a sign to unbelievers to convince them. (“The Sign of Jonah” = the resurrection) So, I see that God uses nature and miracles to persuade, which can be assessed using scientific and historical methods. Can anyone find me a clear statement in the Bible that states that only pre-suppositional arguments should be used? I could be wrong, and I am willing to be proven wrong. I think we should use the Biblical method of apologetics, not the fallen man’s method of apologetics.

Presuppositional arguments, like the ontological argument from reason or the epistemological argument from reason are good. Presuppositionalism as a system is not good. It’s good to learn presuppositional arguments, but as part of a quiver of arguments – not in isolation.

By the way, Eric Chabot posted a fascinating discussion between presuppositionalist James White and Richard Howe on this topic, where the point about how presupositionalism cannot prove Christianity in particular came up.

Presuppositionalism is not a Christian methodology. It’s neither Biblical, nor can it be used to prove Christianity. It’s man’s system of apologetics, not God’s.

UPDATE: David Haines posted a couple of criticisms of presuppositionalism here.

UPDATE: A rebuttal to the first of Messianic Drew’s points is here.