I believe your thinking of Barth. Barth was the one who completely discounted general revelation. What Van Til said was that natural revelation was at best partially accessible. (unless of course, he was, gulp, a hyper-calvinist. We'll have to ask Steve, he met the guy.)
OK, time to delineate terms. Aquinas was known for his theory of Natural Law/Theology that states common grace affected all men with reason. The natural outcome of developing a theology based on reason was an apologetic based on human rational defense. Schleiermacher was the theologian most influenced by Kant and thus his subjective theology based on feelings, nothing more than feelings. (social gospel?) Then along comes Barth who refuses to accept any natural/general revelation, be it reason or feelings; and denied the Bible as a special revelation. His only source of revelation was Jesus Christ. Thus, we are only left with Van Til and his presuppositionalism which is based on the authority of the Bible, which was what Luther and Calvin based their theology upon, sola scriptura.
As far as what this article is saying, Van Til is following Calvin and rejecting any notion of a natural theology.
OK, time to delineate terms. Aquinas was known for his theory of Natural Law/Theology that states common grace affected all men with reason. The natural outcome of developing a theology based on reason was an apologetic based on human rational defense. Schleiermacher was the theologian most influenced by Kant and thus his subjective theology based on feelings, nothing more than feelings. (social gospel?) Then along comes Barth who refuses to accept any natural/general revelation, be it reason or feelings; and denied the Bible as a special revelation. His only source of revelation was Jesus Christ. Thus, we are only left with Van Til and his presuppositionalism which is based on the authority of the Bible, which was what Luther and Calvin based their theology upon, sola scriptura.
The traditional method, offered first in detail by Thomas Aquinas in its Catholic form and by Joseph Butler in its Protestant form (but being in principle that offered by the very earliest of apologists), is based upon the assumption that man has some measure of autonomy, that the space-time world is in some measure "contingent" and that man must create for himself his own epistemology in an ultimate sense. The traditional method was concessive on these basic points on which it should have demanded surrender! As such, it was always sell-frustrating. The traditional method had explicitly built into it the right and ability of the natural man, apart from the work of the Spirit of God, to be the judge of the claim of the authoritative Word of God. It is man who, by means of his self-established intellectual tools, puts his "stamp of approval" on the Word of God and then, only after that grand act, does he listen to it. God's Word must first pass man's tests of good and evil, truth and falsity. But once you tell a non-Christian this, why should he be worried by anything else that you say. You have already told him he is quite all right just the way he is! Then the Scripture is not correct when it talks of "darkened minds," "wilful ignorance," "dead men," and "blind people"! With this method the correctness of the natural man's problematics is endorsed. That is all he needs to reject the Christian faith.Van Til is rejecting the traditional method of apolegetics, that believed that natural man could see God's creation and come to certain conclusions about the reality of God, without Scripture.
As I said, Van Til apologetics is really an anti-apologetic and a rejection of Rom.1:19-20 and Psa.19