The Central Point of the Transcendental Argument for Christianity
What is the big claim made by the transcendental argument? No one puts it better than Cornelius Van Til himself:
Only the Christian theory of knowledge, based as it is upon the absolute authority of the word of God speaking in Scripture, makes communication of any sort possible anywhere between men. Without this presupposition man would have no integrated selves and the world would be a vacuum. Without this presupposition of the Christian theory of being there would be no defensible position with respect to the relation of men and things. Neither man nor things would have discernible identity. There would be no science and no philosophy or theology, for there would be no order. History would be utterly unintelligible. Finally, without the presupposition of the Christian theory of morality there would be no intelligible view of the difference between good and evil. Why should any action be thought to be better than any other except on the supposition that it is or it is not what God approves or disapproves? Except on the Christian basis there is no intelligible distinction between good and evil.
-Cornelius Van Til, The Doctrine of Scripture, 61-62