Ontological Argument for the Existence of God Explained
This paper critically examines the ontological argument for the existence of God across historical and contemporary contexts. Beginning with Saint Anselm of Canterbury's twelfth-century formulation in the Proslogium, the paper traces the argument's development through René Descartes' seventeenth-century Meditations and R. G. Collingwood's twentieth-century reassessment. It explores the logical structure of the argument — that a being "than which no greater can be conceived" must necessarily exist — alongside modern challenges posed by scientific inquiry, the problem of evil, and the growing demand for empirical proof. The paper concludes that while the a priori basis of the ontological argument remains philosophically contested, its core reasoning continues to carry relevance for theologians and philosophers alike.
- Introduction: Purpose and scope of the ontological argument study
- Historical Ontological Arguments for the Existence of God: Anselm and Descartes formulate the core argument
- Contemporary Ontological Arguments for the Existence of God: Modern challenges, cosmology, and the problem of evil
- Conclusion: Argument's enduring relevance in a scientific age
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What makes this paper effective
- The paper traces the ontological argument chronologically — from Anselm through Descartes to twentieth- and twenty-first-century responses — giving the analysis a clear developmental arc.
- It balances primary philosophical sources (Anselm's Proslogium, Descartes' Meditations) with secondary scholarly commentary, grounding abstract claims in cited authority.
- The numbered syllogistic summary of Anselm's argument provides concrete logical structure, making an abstract philosophical debate accessible to readers.
Key academic technique demonstrated
The paper demonstrates effective use of the reductio ad absurdum as a rhetorical and analytical framework. By presenting Anselm's argument on its own logical terms — showing that the denial of God's existence produces a self-contradiction — the writer explains not just what the argument claims but how it functions as a form of proof. This technique is then used to evaluate both supporting and opposing positions throughout the essay.
Structure breakdown
The paper is divided into four sections: an introduction establishing the study's purpose; a historical survey covering Anselm and Descartes; a contemporary section addressing twentieth-century and modern responses including Collingwood, the problem of evil, and cosmological theistic arguments; and a brief conclusion that contextualizes the argument's enduring relevance against modern empirical standards. The structure moves logically from historical foundation to present-day debate.
Introduction
One of the irrefutable facts about the history of humankind has been the existence of various types of religions since time immemorial. Ancient peoples looked at the sky and the world around them in wonder and instinctively sought to identify the source of all of this miraculous creation. It is not surprising, then, that belief in the existence of God can be said to be as old as humankind itself. The purpose of this study is to provide a critical analysis of the relevant literature concerning the historical and contemporary ontological argument for the existence of God, and to synthesize these findings into a coherent analysis that can serve as a foundation for further research.
Historical Ontological Arguments for the Existence of God
One authority reports that, "One of the most fascinating arguments for the existence of an all-perfect God is the ontological argument. While there are several different versions of the argument, all purport to show that it is self-contradictory to deny that there exists a greatest possible being. Thus, on this general line of argument, it is a necessary truth that such a being exists; and this being is the God of traditional Western theism."1 From an ontological perspective, then, the existence of God is an a priori reality even when mere humans fail to cognitively grasp and consciously concede this reality. Consequently, the arguments in support of the existence of the "God of traditional Western theism" all stem from this a priori assumption, making the analysis somewhat circular and therefore confounding for many biblical scholars.2
While the seemingly legitimate argument can be made that the existence of God can be proven by "just looking around," theologians and laypersons alike are vitally interested in delving further into the issue in ways that can provide more concrete evidence to support this view. As Jesus made clear in Luke 4:12, "It is said: 'Do not put the Lord your God to the test.'" Nevertheless, this admonition has not stopped countless individuals from seeking some type of proof positive that they can point to in order to reassure themselves and their fellow humans that there is indeed a "greatest being" in the universe who is responsible for all of the creation around them.
One of the early proponents of the ontological argument in support of the existence of God was Saint Anselm of Canterbury.3 According to Anselm's perspective, written in the early twelfth century, the mysteries that abound in the world are sufficient evidence to confirm the existence of God, and it would be foolhardy to argue otherwise. As one authority notes, "St. Anselm's version of the ontological argument appears in his Proslogium, Chapter II, and is the definitive statement of the argument."4 In that chapter, Anselm writes: "Truly there is a God, although the fool hath said in his heart, There is no God,"5 and then goes on to explain why in detail. As a relevant analogy, Anselm argues that, "When a painter first conceives of what he will afterwards perform, he has it in his understanding, but he does not yet understand it to be, because he has not yet performed it. But after he has made the painting, he both has it in his understanding, and he understands that it exists, because he has made it."6
In sum, Anselm maintains that humanity depends on experiential sources to confirm or refute abstract conceptualizations, including most especially the fundamental hypothesis concerning the existence or nonexistence of God. This reliance on experience, however, flies in the face of what Anselm contends is the overarching reality of God's existence. One biblical authority points out that Anselm's argument assumes "the form of a reductio ad absurdum, which means that it takes a hypothesis, shows that it has absurd or otherwise unacceptable implications, and so concludes that the hypothesis is false. In the case of Anselm's ontological argument, the hypothesis treated in this way is the hypothesis that God does not exist. Anselm's argument rests upon the conception of God as 'that than which no greater can be conceived.' It is this conception of God with which the hypothesis that God does not exist is supposed to conflict."7
In truth, the hypothesis that God does not exist would appear on its face to be as problematic to confirm or refute as its corollary, but this profound constraint has not stopped humanity from making the attempt. Speculations and conjectures have always abounded concerning problem statements such as whether, if there is a God, he can create a boulder so large that even he cannot move it, and in some ways this same reasoning applies to the ontological argument in support of the existence of God. Anselm asserts that:
If God is that than which no greater can be conceived, then nothing can be imagined that is greater than God. If God does not exist, though, then something can be imagined that is greater than God — namely, a God that does exist. Obviously this is impossible. Hence, there is no doubt that there exists a being than which nothing greater can be conceived, and it exists both in the understanding and in reality.8
In sharp contrast to the modern scientific method — whereby a hypothesis is first propounded, methods are formulated to test it, and a conclusion is drawn from the resulting empirical observations — the ontological argumentative approach begins with a hypothesis that cannot be logically refuted. Arguments to the contrary are regarded as either misinformed, ill-intentioned, or ignorant of the reality of God's existence, and are therefore considered erroneous. This apparently unassailable position, of course, invites the attempt at refutation, but the ontological arguments in support of the existence of God do not brook it.
The rationale in support of this irrefutable position is based squarely on the aforementioned logical paradox: "The hypothesis that God does not exist thus seems to give rise to a logical absurdity: that there both is and is not something that can be imagined that is greater than God. There is, because it is possible to imagine a God that does exist. There isn't, because it is impossible to imagine something greater than the greatest thing imaginable."9 In other words, like young children arguing over what number is the largest ("Infinity plus one"), the arguments against the existence of God pale when compared to his truly ubiquitous and omnipotent nature, which precludes superlative comparisons. As Anselm concludes, "A hypothesis that gives rise to a logical absurdity, though, must be false. The hypothesis that God does not exist, therefore, is false; God exists."10
A form of Anselm's ontological argument in support of the existence of God is summarized below.
(1) God is that than which no greater can be conceived.
(2) If God is that than which no greater can be conceived, then there is nothing greater than God that can be imagined.
Therefore: (3) There is nothing greater than God that can be imagined.
(4) If God does not exist, then there is something greater than God that can be imagined.
Therefore: (5) God exists.11
Based on the argument's first premise (1), the conceptualization of God propounded by Anselm (2) should be regarded as an obvious truth based on humanity's inability to conceptualize any greater entity (3). As a result, Anselm's final premise (4) naturally follows from this line of reasoning.12
During the seventeenth century, René Descartes took up a similar argument in support of the existence of God in his Fifth Meditation, wherein he "claims to provide a proof demonstrating the existence of God from the idea of a supremely perfect being [arguing] that there is no less contradiction in conceiving a supremely perfect being who lacks existence than there is in conceiving a triangle whose interior angles do not sum to 180 degrees."13 When Descartes argued, Cogito ergo sum ["I think therefore I am"], he was making essentially the same point as his defense of the ontological arguments in support of the existence of God. Like the somewhat circular reasoning advanced by Saint Anselm, Descartes' argument likewise depends on some convoluted logical gymnastics to fully comprehend, but the end result of all such reasoning is the same. As Descartes concluded, "Since we do conceive a supremely perfect being — we do have the idea of a supremely perfect being — we must conclude that a supremely perfect being exists."14
Notwithstanding the persuasive and conclusive nature of the argument advanced by Descartes and like-minded theologians, the nebulousness of the underlying concepts has precluded their universal acceptance. Nevertheless, proponents of the ontological arguments turn to the same logical processes that Saint Anselm drew on to support their beliefs. According to Flage, "Anyone who reads the Meditations will grant that clear and distinct ideas are capable of representing things distinct from themselves, that they typically represent the essences of kinds of things, and that the ideas of essences divide things in the world into kinds. That clear and distinct ideas are representative or capable of representing is implied by his paradigmatic examples: the ideas of the self [and] God."15
In the millennium that has passed since Saint Anselm first formulated his classic ontological argument in support of the existence of God, there has been relentless scholarship focused on developing a better understanding of these logical arguments and developing theses both in support of and against them.
Conclusion
One of the unfortunate consequences of the human condition is that people, especially in the twenty-first century, are experiential creatures that typically demand some type of scientific proof before they will accept something as the absolute truth. The situation for modern humanity stands in stark contrast to the Middle Ages, when Saint Anselm first propounded his ontological arguments in support of the existence of God and the vast majority of humankind was not only willing but ready to receive truth from those in an authoritative position to know it. One thousand years ago, the a priori arguments that firmly refuted any suggestion that God does not exist were widely regarded as concrete evidence of the existence of a Supreme Being greater than anything mere humans could conceive.
While humans living in the Middle Ages were as intelligent as modern humans, they lacked access to the greater stores of information available to their twenty-first-century counterparts, and it is little wonder that the ontological arguments in support of the existence of God have come under increased scrutiny from all quarters. Despite this increased scrutiny, the same rationale applied to Saint Anselm's ontological arguments in the Middle Ages remains relevant today, and still draws on the "just look around" appeal to support its validity.
References
Alekseyev, Yaroslav. "Is the Universe Acausal, and Does God Exist?" Skeptic 10 (3, Fall 2003), 23–25.
Braungardt, Jurgen (2018). "Ontological Arguments for the Existence of God." [online] available: http://braungardt.trialectics.com/theology-index/problems/ontological-arguments/.
Collingwood, R. G. "Lectures on the Ontological Proof of the Existence of God. Written December 1919 for delivery Hilary Term 1920." Department of Western Manuscripts, Bodleian Library, Oxford.
Deane, Sidney N. (1903). Works of St. Anselm. [online] available: sacred-texts.com.
Flage, Daniel E. "Descartes and the Real Distinction between Mind and Body." The Review of Metaphysics 68 (1, September 2014), 93.
Himma, Kenneth E. (2018). "Anselm: Ontological Argument for God's Existence." Internet Encyclopedia of Philosophy. [online] available: https://www.iep.utm.edu/ont-arg/.
Lobont, Florin. "Ontological Proof and the Critique of Religious Experience." Journal for the Study of Religions and Ideologies 9 (2, Winter 2010), 157–161.
Pasquarello, Tony. "God: 12,000; the Faith of a Rebeliever." Free Inquiry 22 (4, Fall 2002), 51.
Pearson, Joseph H. "The Cambridge Companion to Anselm / Anselm of Canterbury and His Theological Inheritance / Anselm of Canterbury: The Beauty of Theology." Anglican Theological Review 88 (1, Winter 2006), 107–113.
Sinitiere, Phillip Luke. "The Medieval Theologians: An Introduction to Theology in the Medieval Period." Journal of the Evangelical Theological Society 46 (1, March 2003), 152–156.
"St Anselm's Ontological Argument" (2018). Philosophy of Religion. [online] available: http://www.philosophyofreligion.info/theistic-proofs/the-ontological-argument/st-anselms-ontological-argument/.
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