by Rick Wade

The twentieth century was a difficult time in the intellectual arena for conservative Christians. Secular scholarship was flexing its muscles, buoyed by the successes of science, and Christian scholars needed to respond. Among those who rose to the challenge of defending orthodox Christianity were Cornelius Van Til, Gordon Clark, Edward John Carnell, and Norman Geisler. Each has had a profound effect on the church. Who were/are these men, and what were/are the distinctives of their apologetics?


Cornelius Van Til (1895-1987) has been called the father of presuppositional apologetics. Van Til earned his B.A. from Calvin College, his Th.M. from Princeton Theological Seminary, and his Ph.D. from Princeton University. He taught briefly at Princeton Seminary before moving to the new Westminster Theological Seminary where he taught for forty-three years. Van Til was ordained with the Orthodox Presby­terian Church. Van Til’s ambition was to base his entire philosophy-metaphysics, epistemology, and ethics-on scriptural revelation. This is the theme of The Defense of the Faith (his most well­ known book on apologetics) and everything else he wrote, including books on evidences, ethics, epistemology, and books on theology. He argued that Reformed theologians should “follow [Reformed] principles in apologetics as well as in theology proper.”1 The only reasonable starting point is the self-revealed God.

Van Til believed that other Reformed theolo­gians were not taking their theology seriously in their apologetics. Charles Hodge, for example, thought that reason had to judge the credibility and evidences of a revelation. Van Til rejected this, claiming that natural man will not interpret evidences in the light of creation. How can one expect fallen and willfully ignorant people to fairly evaluate the evidences and arguments of traditional apologetics as long as their wrong presuppositions are not challenged? “If this is done, we are virtually telling the natural man to accept just so much and no more of Christi­anity as, with his perverted concept of human nature, he cares to accept.”2

“To argue by presupposition,” Van Til wrote, “is to indicate what are the epistemological and metaphysical principles that underlie and control one’s method. The Reformed apologist will frankly admit that his own methodology presupposes the truth of Christian theism.”3

Van Til did not use traditional theistic proofs because they make God’s existence at best highly probable, while the Bible says God has revealed Himself so clearly that everyone knows He exists. He used, rather, a transcendental argument, namely, that only Christianity is capable of supporting intelligible predication. As creator of the universe, God has all knowledge of it. As creatures, we do not. God is thus the only one who has the true interpretation of reality. “The only ‘proof’ of the Christian position,” Van Til explained, “is that unless its truth is presupposed there is no possibility of ‘proving’ anything at all.”4

Other apologists accuse Van Til of putting the cart before the horse by not establishing an epistemology before dealing with metaphysics. He said it isn’t an either/or; we get both together in the God Who has revealed Himself. And this starting point should be made clear.

Other criticisms have been leveled at Van Til, including some from other presupposition­alists. One criticism is that Van Til claims too much. The apologist has to be ready to show why every attribute of God is necessary for intel­ligible predication. Thus, John Frame believes that “Van Til’s conclusion is better described as a goal of apologetics. To call it a conclusion is to suggest that every apologetic encounter … must end by establishing the necessity of presupposing God for universal intelligibility.”5



Gordon H. Clark (1902-1985) was a prominent Christian philosopher in the mid-twentieth century. After completing his bachelor’s degree in French and his doctorate in philosophy at the University of Pennsylvania, Clark taught philosophy at his alma mater, Wheaton College, and at Butler University. He was ordained with the Orthodox Presbyterian Church, but later moved to the Reformed Pres­byterian Church.

Clark’s apologetic method has been called “axiomatic-deductive presuppositionalism.”6 Like Van Til, Clark begins with the self-revealed God. However, he frames the starting point as an axiom, and in keeping with his strict rationalism, he defends Christianity like a philosophical system, with strict attention paid to the laws of logic. In his 1965 lecture, Clark named as his axiom, “The Bible is the Word of God.”7 George Mavrodes charged that from this simple phrase one cannot deduce anything of importance.8 Clark responded that the axiom isn’t just a set of empty words with no content.9 “Embedded in it [is] the law of contradiction, plus the nature of God…plus the thousands of propositions thus declared true.”10

The apagogic method was Clark’s favorite tool for showing the futility of secular philosophies. In A Christian View of Men and Things, his most wide-ranging analysis of this kind, he takes on opposing views of history, politics, ethics, science, religion, and epistemology. His goal is “to show that Christian theism is self-consistent and that several other philosophies are inconsistent, skeptical, and therefore erroneous.”11

Clark rejected empirical philosophies because they cannot derive any norms or laws of logic such as the law of contradiction from sense experience. “And without the law of contradiction,” he wrote, “it is impossible to say anything meaningful….[I]f all knowledge is based on experience, there is no knowledge.”12 There must be prior innate knowledge by which to structure sense experience. A person can see God in nature, but that is “because he already knows God in his mind. Instead of building up a knowledge of God through a careful examination of empirical data, we recognize God’s handiwork in nature.”13

One criticism of Clark’s method is that, because we are not omniscient, we can never be sure we have found the one true system. He acknowledged this weakness. If confronted by two incomplete systems, both of which are logically consistent, we simply have to choose:

No philosopher is perfect and no system can give man omniscience. But if one system can provide plausible solutions to many problems while another leaves too many questions unanswered, if one system tends less to skepticism and gives more meaning to life, if one world view is consistent while others are self contradictory, who can deny us, since we must choose, the right to choose the more promising first principle?14



Edward John Carnell (1919-1967) earned his B.A. in philosophy at Wheaton under Gordon Clark, his Th.B. and Th.M. at Westminster under Van Til, his Th.D. at Harvard, and his Ph.D. at Boston University. He taught at Fuller for nineteen years until his untimely death in 1967.

In mid-century a group of Bible scholars and theologians who were being called “new evan­gelicals” or “neo-evangelicals” banded together to form Fuller Theological Seminary to address the intellectual challenges of the day. According to historian George Marsden, Carnell was “the recognized leading scholarly spokesman for the new evangelicalism.”15 He was a brilliant man. In fact, Carl Henry opposed the appointment of Carnell to the office of president because his scholarship was dearly needed, and his admin­istrative duties would take him away from it.

Tensions mounted among fundamental­ists who feared the “neo-evangelicals” would drift from orthodox theology because of the influence of   modern thought. Carnell did doctoral work on Reinhold Niebuhr and Soren Kierkegaard. Kierkegaard’s influence can be seen in Carnell’s addition of a third kind of truth-truth as personal rectitude-to the two kinds typically accepted: truth as what is (“ontological truth”) and truth as inferred (“propositional correspondence to reality”).16 By truth as personal rectitude he meant being true to what we know we should be morally. It does little good to know what is real and to be able to infer whole systems of thought if a person rejects the moral sense.

Carnell agreed with Van Til and Clark regarding the starting point: the self-revealed God. To make a case for it, he referred to what he called the “synoptic” starting point. This is our internal effable experience, universal principles known immediately by all people. To verify this starting point, he employed the method of systematic consistency to analyze the internal logical consistency (the horizontal element) and the factual accuracy (the vertical element) of a worldview. This put him at odds with Van Til, for, unlike his teacher, he framed the logical starting point as an hypothesis rather than as authoritative and necessary.

Positively, Carnell  sought to discover whether “Christianity … can live up to its lofty claims by giving a basis of personal hope in immortality, a rational view of the universe, and a solution to the problem of truth.” Negatively, he asked “what one is left with if he gives up a given hypothesis.”17 To give up Christianity, he believed, is to wind up with skepticism.

To build a case for the faith that would be heard, Carnell looked for particular points of contact with unbelievers. His award-winning first book, An Introduction to Christian Apologetics, looked to logical consistency and factual accuracy. In other writings he looked to values, the judicial sentiment, and the law of love. He believed these are viable points of contact because they are ours by virtue of our humanity. As Gordon Lewis wrote, “in presenting and defending the Christian hypothesis, the apologist can count on these realities. If non-Christians do not admit them explicitly, they are present implicitly.”18

Norman Geisler
Norman L. Geisler (1932-) has been one of the most prominent apologists in America for several decades. He earned his B.A. in philosophy and M.A. in theology at Wheaton College, his Th.B. at William Tyndale College, and his Ph.D. in philosophy from Loyola University in Chicago.

Geisler has taught at Christian colleges and seminaries for over fifty years, including Trinity Evangelical Divinity School, Dallas Theological Seminary and Southern Evangelical Seminary which he co-founded and where he continues to teach. He has authored or co-authored over sixty books addressing philosophy, theology, biblical studies, and worldviews. A perusal of the Baker Encyclopedia of Christian Apologetics shows a familiarity with a remarkable variety of issues.

Geisler’s approach to apologetics is significantly different from that of Clark, Carnell, and Van Til. He is a classical (Thomistic) apologist (i.e., a devotee of Thomas Aquinas), a badge he wears proudly, “I gladly confess,” he writes, “that the highest compliment that could be paid to me as a Christian philosopher, apologist, and theologian, is to call me ‘Thomistic’.” Evangelicals have been far too quick to dismiss this great Medieval thinker to whom they owe a great debt, Geisler insists.19

In his widely used text Christian Apologetics, Geisler employs the test of un-affirmability to make a case against opposing worldviews, and that of undeniability to make a case for theism. He turns to undeniability because an argument can follow the laws of logic without truly stating the way things are. As an example he says, “No logical necessity is grounding my existence….Of course, I must exist in order to conceive of my nonexistence. But the ‘must exist’ does not mean ‘logically must’ but only ‘actually must’.20 So it is logically possible that I not exist, but it is undeniable that I do.

Geisler’s argument for theism is tied tightly with first principles of logic. In a series of thirteen steps he employs the principles of existence, existential contingency, causality, noncontradiction, and analogy among others.21 He notes that “the basic theistic argument … can be summarized as follows: Every effect has a cause; the world is an effect; therefore, the world has a cause.”22

Once a metaphysics is in place, Geisler shifts to the test of systematic consistency to make a case for Christianity (over Judaism and Islam, the other two major theistic worldviews). He begins with a case for miracles moves to an argument for the historical reliability of the Bible, then for the deity of Christ, and then back to Scripture for a defense of its divine authority and inerrancy.23

There are a few differences between the case built in Christian Apologetics and that made in a book co-authored with Frank Turek. In the latter, the authors begin with the subject of the knowability of truth, a problem which has spilled out of the academy into the public arena, and they draw heavily from new discoveries in science (e.g., the Anthropic Principle, DNA, the Intelligent Design movement).

Contrasting Views
While there are points of agreement in method and content between these apologists, the nature of the starting point, the place of factual evidence, and the method of reasoning distinguishes them.

Loyal presuppositionalists continue in Van Til’s vein, although sometimes with modifications as with Frame. Carnell’s systematic consistency argument is used by such apologists as William Lane Craig and Geisler. Geisler’s wide-ranging writings and lectures continue to provide plenty of material for both scholarly and popular apologetics. Not many apologists stay within the confines of Clark’s strict rationalism, but one would be hard-pressed to find a keener logical mind to help uncover the contradictions in other worldviews. Time spent in all four scholars will benefit anyone interested in defending the faith, even in these postmodern times.

Rick Wade is a Research Associate with Probe Ministries (


1 Cornelius Van Til, The Defense of the Faith, 3″1 ed. (Phillipsburg, N.J.: Presbyterian and Reformed, 1967), 79-80.

2 Ibid., 81.

3 Ibid., 99.

4 Cornelius Van Til, “My Credo,” in E. R. Geehan, ed., Jerusalem and Athens: Critical Discussions on the Philosophy and Apologetics of Cornelius Van Til (Phillipsburg, N. J.: Presbyterian and Reformed, 1971), 21.

5 John M. Frame, Cornelius Van Til: An Analysis of His Thought (Phillipsburg, N.J.: P & R Publishing, 1995), 316-17.

6 John Warwick Montgomery, “Clark’s Philosophy of History,” in Ronald H. Nash, ed., The Philosophy of Gordon H. Clark (Philadelphia: Presbyterian and Reformed, 1968), 354.

7 Gordon Clark, “The Axiom of Revelation,” in Nash, ed., The Philosophy of Gordon H. Clark, 88.

8 George I. Mavrodes, “Revelation and Epistemology,” in Nash, ed. The Philosophy of Gordon H. Clark, 228- 237.

9 Clark, “Reply to George I. Mavrodes,” in Nash, ed. The Philosophy of Gordon H. Clark,441-42.

10 Clark, “Axiom,” 88.

11 Gordon H. Clark, A Christian View of Men and Things (Grand Rapids: Eerdmans, 1952),324.

12 Clark, Christian View, 308-09.

13 Ronald Nash, “Clark’s Theory of Knowledge,” in Nash, , ed. The Philosophy of Gordon H. Clark, 15 7. 14 Clark, Christian View, 34.

15 George Marsden, Reforming Fundamentalism: Fuller Seminary and the New Evangelicalism (Grand Rapids: Eerdmans, 198 7), 180-181.

16 Edward John Carnell, Christian Commitment: An Apologetic (New York: Macmillan, 1957), 29.

17 Edward John Carnell, An Introduction to Christian Apologetics (Grand Rapids: Eerdmans, 1948), 97.

18 Gordon R. Lewis, Testing Christianity’s Truth Claims: Approaches to Christian Apologetics (Chicago: Moody Press, 1980), 183.

19 Norman Geisler, Thomas Aquinas: An Evangelical Appraisal (Eugene, OR: Wipf and Stock Publishers, 2003), 14-18.

20 Norman Geisler, Christian Apologetics (Grand Rapids: Baker, 1976), 144.

21 Norman Geisler, Baker Encyclopedia of Christian Apologetics (Grand Rapids: Baker, 1999), “God, Existence of.”

22 Geisler, Christian Apologetics, 253.

23 See also Norman L. Geisler and Frank Turek, Don’t Have Enough Faith to Be an Atheist (Wheaton: Crossway, 2004), chap. 14.