That isn't a word, but it should be! In the middle part of the twentieth century, such divergent voices as Karl Barth and D. Martyn Lloyd-Jones cast doubts upon the whole enterprise of apologetics --how to defend the faith. Both favored Christian proclamation over Christian argumentation. I resonate with that, a bit, if we view apologetics as two men seated on a podium, bandying about truth as if it were a ping-pong ball, a set of intellectual propositions with no practical application.
That said, defending the faith is a useful thing. It is useful in Christian proclamation as a way of placing underpinnings beneath Christian convictions -- here is why we believe certain things to be true. Some effective modern Christian communicators, Ravi Zacharias among them, have shown the use of apologetics in its full flower --as a way of evangelizing the lost, of giving a credible Christian message to thinking audiences, hence evangelapologetics.
I am not one to get fussy over apologetic method. I am far more interested in applied apologetics than I am in aruging about the theory that lies behind this or that line of argument. I think that the classical proofs for God are of use. Yet, I acknowledge that classical proofs, apart from revelation, can get us only so far towards the Biblical notion of God's person and his work. What classical proofs can show us about God roughly lines up with what Paul says everybody knows about God in Romans 1 and 2 --that there is a God, and certain things about his nature --that he is all-powerful and all-just, etc. Classical proofs can get us nowhere near God as he is revealed to us in Christ, or the message of redemption. Classical proofs align roughly with what we call general or natural revelation.
This is why I gravitate more towards a generally presuppositional approach. I say "generally" because my knowledge is not nuanced enough to tease out all the differences that exist. I do, however, feel a bit compelled to speak about it in light of what Professor Paul Copan writes about it over at The Gospel Coalition. The presuppositionalism he critiques there is unrecognizable to me. If presuppositionalism were what Copan describes, then nobody would believe it to be true. My purpose here is not to trash other ways of doing apologetics, but rather to explain what presuppositionalism really is. Professor William Edgar did it probably better and certainly briefer here: Fides Quaerens Intellectam.
What is presuppositionalism? Many people dismiss it because they think it begins with assuming what it ought to prove, namely that God exists, and the God that exists is the God who reveals himself in Scripture. Some may argue that way, but I think presuppositionalism begins with some basic acknowledgments about how we know what we know. It does not assume that man can or does come to his knowledge about life, the universe, and everything from outside the system as an objective observer. He does not have the benefit of objectivity or omniscience. He discerns truth as one within the system and as a part of the system. He is a created being, how can he know what lies beyond creation or interpret creation in any meaningful way? Moreover, he approaches what he sees and hears not with a completely open mind but rather with certain preconceived notions about what it all means. These notions can be examined and amended, but they are inevitably there.
The first question, then, is not about what we know (the content of knowledge or belief) but about how we know what we know. The first question is not "Does God exist?" but "How do I come to know anything?" You can see this reality reflected in the structure of the Westminster Confession of Faith which begins, not with a statement of beliefs about God, but a statement of beliefs about how God makes himself known. The Christian answer to the question "How can I know anything?' must be "Only because God has revealed it to me, either through his words or his works." This is where many thinking people accuse presuppositional apologetics of circular logic --assuming that God exists in order to prove that God exists.
Yet, this misses the point. The presuppositionalist understands the purpose of apologetics is to demonstrate the truth of God to those disinclined to believe it, and, what is more, that it is more important to win a heart than an argument. He simply goes about it in a different way. His way is to invite those who see the world differently than he does to view the world through his eyes, if only for the sake of argument. His desire to win them over expresses itself by showing others the logical coherence of the Christian message. His basic premise is that the truth is coherent and consistent and falsehood, by definition, is incoherent and inconsistent. So, even as he demonstrates the consistency of the Christian world-and-life-view, he points out the inconsistency of other world-and-life-views. His arguments are not based so much on proofs as they are consistency. His question to his conversation partner is, given these particular presuppositions, does this view not make sense?
Picture two men at a boat show. There are many boats for sale. One man is a representative for a particular brand of boat; the other man is a prospective buyer looking to trade up from his current boat. He believes in his product. He knows why his boat is superior to all other boats. He knows the ins and outs of all the mechanicals, the materials, the power and hydrodynamics. Yet, at the forefront of his mind is this: he believes in his product, he knows, in his heart of hearts that it is the most excellent product out there. He knows the real questions of the buyer are "Why is this boat better than mine? Is it faster? Will it float? Does it leak? Is it reliable? He knows the best way to make the sale is to put the boat in the water and let the man drive it. If it truly is a superior product, the boat will sell itself. What is more, the salesman is so secure that his product is the far superior one, that he might invite the buyer to drive other boats. He might go along with him and point out where the other boats fall short of his boat --inferior grommets that might give way, inferior engine design, cheaper parts that will not hold up. The other boats may look pretty but they will get you only so far.
If the Christian faith is true, it must be consistent. If it is true and all other systems of thought are false, then they must necessarily be inconsistent. Yet, to argue that other systems are false is not to argue that they contain no truths whatsoever. To have any credibility, they must accommodate themselves to reality in some sense, they have to speak in some meaningful way to the questions humans inevitably have about the meaning of life, eternity and morality. The Christian asserts that these truths are borrowed from the Truth, which is found only in Christ. The truths found in other religions give us meaningful points of contact to engage with adherents of other world and life views, not for the purpose of demonstrating how much they have in common with Christianity, but rather to demonstrate how those fixed realities to which they accomodate themselves actually unravel the system. For instance, Christianity, modern Judaism and Islam all believe in a God who both is morally perfect and rightly demands moral perfection --in other words, a God who is just. This presents a problem, however. Man is not morally perfect. How can sinful man find favor with an inflexibly holy God? There is only one possible consistent answer. It cannot be that this God regards those who live basically obedient lives. No just judge on earth would look at a murderer and pardon him because of the many other good things he did in his life. That would offend our innate sense of justice! The only logically consistent answer is that such a God must punish sin. The only answer then, that gives relief to such a conundrum is the cross of Christ.
What the presuppositionalist does, in light of such an argument, is this. He takes a commonly believed truth, and uses it to deconstruct the false systems and demonstrate the consistency of the true. He is not "proving" anything, but demonstrating rather the beauty and love of the Christian system. He realizes an argument cannot win the heart, but it can show that the truth about God is both logical and lovely.
The presuppositionalist finds his points of contact with unbelievers not in abstractions or philosophy, but rather from what the Word of God tells us about all humans, believers and unbelievers. Man's chief problem is not the objections of his mind (though it is wrong to discount them) but the autonomy of his heart. Scripture tells us that all humanity knows there is a God and yet suppresses that truth in unrighteousness (Romans 1:18). They know this because God has made it plain to them (Romans 1:19). What is more, all humanity knows there is a moral code, and understands the just sanctions for breaking that moral code, and yet not only breaks it, but teaches that breaking it is a virtue (Romans 1:32). This is not just abstract knowledge, but every person's personal experience. Any time we pass judgment, rightly or wrongly, on the behavior of another, we have demonstrated our knowledge of the fixed verity of the existence of right and wrong (Romans 2:1). Though philosophers have long tried to account for the existence of a moral compass and conscience by locating it somewhere in creation, this enterprise has failed. We can thank Nietzsche and those who followed him for finally killing it off with horrific aplomb. A transcendent moral norm is not a material or created entity. It must come from somewhere else. Other examples could be added: the reality of love, for one. Paul uses these basic facts about human nature: man's creation in the image of God, his rebellion against God, and his knowledge that he has rebelled against God as the dark intellectual and experiential underpinnings upon which to build the beautiful reality of the grace of God experienced solely in his own Son. This presuppositionalist humbly submits that we should, too.