"Common ground" is not "neutral ground"

Greg Bahnsen made the following observations regarding Van Til's teaching about "common ground," originally published in an issue of the SCCCS Penpoint newsletter (I've edited it slightly here for brevity and clarity):

   Cornelius Van Til was granted a God-honoring, biblical clarity about the issue of "common ground" between those who adhere to the Scriptures and those who repudiate or compromise the teaching of God's word — whether outright unbelievers or followers of false religions, theological modernism, Romanism, or the cults.

   Van Til called for faithfulness to the Lordship of Christ in all of our thinking.  Thus our ultimate presuppositions must regulate every phase of our reasoning, including our argumentation in defense of the faith.  There is no neutrality.  Only the presupposed truth of God's self-revelation — which all men know even if suppressed in unrighteousness — makes intelligible their claims to knowledge about anything whatsoever and makes justification of those claims possible.  Thus the all-encompassing apologetical challenge issued by Van Til was that without the Christian God men could not, in principle, prove or know anything at all.

  Van Til wrote:

The implication of this for Christian apologetics is plain.  There can be no appeasement between those who presuppose in all their thought the sovereign God and those who presuppose in all their thought the would-be sovereign man.  There can be no other point of contact between them than that of head-on collision. (The Intellectual Challenge of the Gospel)

   Van Til's critics sometimes misconstrued this challenge as saying that there is no common ground between the thinking of believers and unbelievers.  Van Til affirmed that there is indeed common ground, but it is not religiously neutral common ground.  He wrote:

It is this fact, that the natural man, using his principles and working on his assumptions, must be hostile in principle at every point to the Christian philosophy of life, that was stressed in the writer's little book, Common Grace.  That all men have all things in common metaphysically and psychologically, was definitely asserted, and further, that the natural man has epistemologically nothing in common with the Christian.  And this latter assertion was qualified by saying that this is so only in principle.…  So far then as men self-consciously work from this principle [of sin, autonomy], they have no notion in common with the believer.  Their epistemology is informed by their ethical hostility to God. (The Defense of the Faith)

   When we deal with men on the level of their theory of knowledge (epistemology), Van Til held that we must remember the doctrine of "total depravity" — and thus challenge in every area of life and at every point all who repudiate or compromise the Scriptures.  In philosophical principle they could not make anything intelligible in any aspect of human experience.