How did Norm Geisler Argue for the Existence of a Theistic God?
[Unfinished draft]
Norm Used Seven Arguments for the Existence of God
Norman L. Geisler was a classical Christian apologist who loved to “destroy arguments and every lofty opinion raised against the knowledge of God” (2 Corinthians 10:5). He gained some notoriety as a powerful debater for God in public debates with noteworthy secular humanists on American college campuses in the 1970s and 1980s. [Need to list which arguments he used in some of the few recordings we have of these early debates.]
In his Systematic Theology, Norm recommends six arguments for God: (1) the horizontal form of the cosmological argument, (2) the vertical form of the cosmological argument, (3) the teleological argument, (4) the ontological argument based on the idea of a Perfect Being, (5) the ontological argument based on the idea of a Necessary Being, (6) the moral argument. [Norman Geisler, Systematic Theology, Volume 1 (Bastion Books 2002, 2025), 27-38. Note that he does not hold that the two forms of the ontological arguments actually prove that a God exists.]
In his “twelve points that show Christianity is true” lectures and book, which he tailored towards college students and the general public, Norm recommends five arguments for the existence of God: (1) the horizontal form of the cosmological argument, (2) the vertical form of the cosmological argument, (3) the teleological argument, (4) the moral argument, and (5) the argument from religious need. [Norman Geisler, The Twelve Points that Show Christianity is True (NGIM, 2012), 16-25.]
In his book Christian Apologetics, Norm offers only one proof for the existence of God, the argument from Being, which he also refers to as the vertical form of the cosmological argument. [Norman Geisler, Christian Apologetics (Baker, 1976), …. Christian Apologetics, Second Edition (Baker, 2013), 265-279.] In 2015, Norm published a booklet titled God: A Philosophical Argument from Being (Bastion Books, 2015) which was essentially this exact same argument with very minor revisions and slight expansion.
Norm Focused on the Metaphysical Argument for God
While he was delighted to use variations of the kalam cosmological argument, teleological arguments, the moral argument, and the argument from religious need to make his cumulative case for the existence of the God of the Bible, he thought the “metaphysical argument” of Aquinas, which he called the “vertical cosmological argument,” was the most profound, most powerful, and most foundational argument for God. “The strongest argument for the existence of God is the ‘vertical form’ of the cosmological argument.” (Reference). It was arguably his favorite meditation and the area that he hoped to see more metaphysical philosophizing devoted to. Towards the end of his life, in 2015, when I asked him what he would do if he had his whole life to live over, without hesitation he said he would earn bachelors, masters, and PhD degrees in philosophy from schools that focused on metaphysics. When he asked me to publish his booklet God: An Argument from Being for him, it was very clear that the topic was extremely dear to his heart and that he was eager to get feedback from other philosophers about any weaknesses in the argument he might reconsider and bolster. [Personal conversations between 2013-2017.]
Not the Same as Leibniz’s Contingency Argument
This thomistic “metaphysical argument” argument is very similar to the more famous “contingency argument” of Gottfried Wilhelm Leibniz and could arguably be classified as a contingency argument. However, Leibniz’s contingency argument uses the principle of sufficient reason (PSR) and Aquinas’s metaphysical argument does not. Norm argued that the use of the PSR made the former logically weaker than the latter (add reference). In some of his earlier public debates with secular humanists, Norm echoed this by using an illustration about effects needing causes, which illustrates the PSR-based argument, taken from Richard Taylor’s book on metaphysics (Reference1, Reference 2).
From Beings to Being?
Norm starts his argument with “Being Is.” Some may argue that the argument goes off the rails here at the outset. What was Norm trying to say?
Norm was trying to argue from being itself rather than from beings. As Wilhelmsen wrote:
The Summa Theolgiae‘s famous “five ways” of proving the existence of God are not strictly metaphysical arguments, for they are rooted in beings rather than in being; the act of existence plays no role in them. Aquinas develops his properly metaphysical argument for the existence of God in On Being and Essence [De ente et essentia.] [Frederick D. Wilhelmsen, The Paradoxical Structure of Existence (Routledge, 2017), xxvi fn. 26
Norm was an Existential Thomist Metaphysician
Norm was known mainly as a classical Christian apologist and as an evangelical theologian. But arguably he was first and foremost a philosopher of existential thomistic metaphysics. He was a thomistic existentialist, an existential thomist. He was intrigued with and encaptivated by “De Ente reasoning” from his introduction to it in 1947 until the end of his life in 2019.
Norm tended to think of Thomism primarily as a moderate realist system of metaphysics and epistemology. He appreciated Gilson, Owens, Wilhelmsen, and the other Existentialist Thomism thinkers in part because they, with their “De Ente reasoning” saw a very powerful argument for the existence of the God of theism.
Norm frequently recommended existential thomists to his students: Étienne Gilson Being and Some Philosophers (1949); Étienne Gilson God and Philosophy (1941); Joseph Owens An Elementary Christian Metaphysics (1963). The syllabi from his “Introduction to Metaphysics” courses at Veritas International University in the 2008-2015 era required the following Thomistic textbooks: Thomas Aquinas, On Being and Essence (de ente et essentia); Étienne Gilson, Unity of Philosophical Experience (1937); Joseph Owens, An Elementary Christian Metaphysics (1963); Reginald Garrigou-LaGrange, God: His Existence and Nature (1934); Frederick Wilhelmsen, Man’s Knowledge of Reality (1959). [https://normangeisler.com/thomism]
His own contributions to Aquinas’s metaphysical argument may be found in several books:
- Thomas Aquinas: An Evangelical Appraisal (Bastion Books, 2025)
- Christian Apologetics, 2nd Edition (Baker, 2012)
- Philosophy of Religion, 2nd Edition (Wipf & Stock, 2004)
- God: A Philosophical Argument from Being (Bastion Books, 2015)
- “God, Evidence for > A Cause Right Now,” The Big Book of Apologetics (Baker, 2012), 196.
- “First Principles,” The Big Book of Apologetics (Baker, 2012), 170-172.
- “The Universe Needs a Cause for its Continuing Existence,” When Skeptics Ask, 2nd Ed. (Baker, 2013), 12-13.
- Twelve Points that Show Christianity is True (NGIM, 2016), 28-30.
- Norman Geisler, Systematic Theology: In One Volume (Bastion Books, 2021), 24-25.
- Video: “Defending the Faith in a Post-Modern World”, 2017. (Ref.)
This unfinished draft is being written by Christopher Haun, webservant of normangeisler.com.