Cornelius Van Til (1895–1987), Reformed theologian and apologist, was born in the Netherlands and completed his Ph.D. at Princeton University in 1927. He taught apologetics for one year at Princeton Theological Seminary but left when the board voted for a reorganization to allow for liberal viewpoints. Van Til and other conservative professors who left Princeton founded Westminster Theological Seminary in Philadelphia. Van Til taught at Westminster from its beginning in 1929 for roughly a half century.

Van Til’s studies of philosophical idealism convinced him that all human thought is governed by presuppositions. (Hence Van Til is sometimes called a “presuppositionalist,” though he was not enthusiastic about that label.) Ultimate presuppositions, he believed, cannot be proved by usual methods, since they serve as the basis of all proof. But they can be proved “transcendentally,” by showing that they are necessary for all rational thought and must be true if there is to be any meaning or order in the world. Van Til sought to reconstruct Christian apologetics so that it would establish the Christian God as the presupposition of human thought, rather than as one rational conclusion among many.

He disparaged the “traditional method” of defending Christianity by theistic proofs and historical evidences, because he believed that tradition began with data considered intelligible apart from God and thereby tried to prove God’s existence. On the contrary, Van Til argued, if we concede that anything is intelligible apart from the God of Scripture, we have lost the battle at the outset. So we should, rather, use a transcendental method, showing that the various forms of non-Christian thought (“would-be autonomous reasoning,” as he put it) reduce to meaninglessness and that only the Christian worldview can make sense of anything.