That which I will attempt to describe in this article is known as presuppositionalism. It is an apologetic method which has had the most impact in Reformed circles, and is most closely associated with Cornelius Van Till, John Frame, and the late Greg Bahnsen.

I should begin by pointing out that the Presuppositional Apologetic does not discount the use of evidences in apologetic reasoning. It does not use evidences in the traditional manner, however. By the traditional manner, I mean using evidences as an appeal to the authority of the unbeliever's autonomous reasoning. The problem is, of course, that the unbeliever cannot reason autonomously. Without God, there would be no possibility of reason. And so the reality of the matter is that every time the unbeliever attempts to reason, he is borrowing from the Christian worldview. That is, he is being inconsistent with his stated presuppositions. And that is the crucial point. Ultimately the intellectual conflict between believers and unbelievers is a matter of antithetical worldviews. The essence of the Presuppositional Apologetic is the attempt to show that the unbeliever's worldview drives him to subjectivity, irrationalism, and moral anarchy. And so the Presuppositional Apologetic calls for the Christian and non-Christian to set side by side their two worldviews and do an internal examination of them both in order to determine whether or not they are consistent even within their own framework. Since God does exist, and since Christianity is true, then any worldview which denies these truths are false and can be demonstrated to be so.

And so, on a practical basis, the first thing to do in a Presuppositional Apologetic is just that which an evidential apologist would not spend a great amount of time on. We listen. We let the unbeliever talk and we let him describe his worldview (i.e., the nature of reality, how the world operates, where it came from, man's place in the world, man's nature, the absence or existence of moral absolutes and the foundation of such, how do we know things and can we know things with certainty, etc.).

The more the unbeliever talks, the more we have to work with. Since his worldview is objectively false, it of necessity contains contradictions (i.e., morality is relative, but he does not live his life on that basis). Morality is absolute, but he cannot account for absolutes without God. We can have knowledge through empirical observation, but he cannot empirically observe that he can have knowledge through empirical observation, etc.

We also demonstrate that whatever objections he may have against Christianity are either a misunderstanding of true Christianity, or that they are not legitimate objections within the Christian worldview. And so we examine the cogency of each side's theory within the respective worldviews. The Christian, within the Christian worldview, can account for rationality, logic, science, morality, etc., because we are thinking God's thoughts after Him, and thus conforming to reality. The unbeliever, since his worldview does not conform to reality (i.e., denies God) cannot account for any of these things.

And so, in a nut shell, the apologist engages in an internal critique of the opposing worldview in order to demonstrate that it is arbitrary (moral relativism, for instance), inconsistent with itself (he knows through observation, but cannot observe that observation is the way to know), and lacks the preconditions for knowing anything at all (he has no basis for the existence of universal abstract entities like logic and morality).

We can then take anything which seems to be important to the unbeliever and demonstrate to him that if his own worldview were true, his belief would be incoherent and/or meaningless.

As Bahnsen says, "In short, the transcendental critique of unbelieving worldviews aims to show that, given their presuppositions, there could be no knowledge in any field whatsoever -- that it would be impossible to find meaning or intelligibility in anything at all."

Note that this is not to say that unbelievers do not reason or communicate or engage in science. It does say that when they do so, they are borrowing from the Christian worldview, which only makes sense, regardless of what they might say, the Bible says that they actually do know God. And it is that triune God of the Bible that is behind all of man's experiences and intellectual efforts. And so the Presuppositional Apologetic recognizes that the critic of Christianity has been secretly presupposing the truth of the faith even as he argues against it. As Bahnsen has said, it is like a person arguing that air does not exist, all the while breathing air as a precondition for his ability to argue.

In conclusion, the only "proof" of Christianity is the impossibility of the contrary. Unless the Christian position is presupposed, at a conscious or unconscious level, there is no possibility for proving anything.

When it is all said and done, the unbeliever will have two options:

1. Acknowledge the truth, or

2. Reject rationality

Many will choose to do just that, although they will deny that is what they are doing. After all, proving is not the same as persuading. But in any case, the apologetic purpose will have been fulfilled. The hope within us will have been defended within the biblical framework.

"Sanctify Christ as Lord in your hearts, always being ready to make a defense to everyone who asks you to give an account for the hope that is in you, yet with gentleness and respect." (1 Peter 3:15)