"Instead of trying to prove the truth of Christianity to the unregenerate, it assumes its truth at the outset and then challenges the natural man by demonstrating that on his presuppositions nothing is true, nothing can be accounted for, and his own thinking is invalid. Van Til thus consistently demonstrates that the natural man dares not be true to his own thinking but must use Christian presuppositions much of the time in order to make science, philosophy, and thought possible. . . . [The Amsterdam tradition] operates on the fundamental faith that unless we presuppose the whole of Christianity we can logically and consistently know nothing, that we either begin with the self-contained God and His eternal decree as man's ultimate environment, as derived from Scripture, or we assume that chance is ultimate, in which case man can know nothing unless he knows everything. And to know everything is especially an impossibility in an evolving universe in which potentiality and possibility are unlimited"