Since on the Reformed basis there is no area of neutrality between the believer and the unbeliever, the argument between them must be indirect. Christians cannot allow the legitimacy of the assumptions that underlie the non-Christian methodology. But they can place themselves upon the position of those whom they are seeking to win to a belief in Christianity for the sake of the argument. And the non-Christian, though not granting the presuppositions from which the Christian works, can nevertheless place himself upon the position of the Christian for the sake of the argument.
– Cornelius Van Til, A Christian Theory of Knowledge p.18