Can God Make a Rock So Big He Can’t Lift It? Why the Limits of Omnipotence Are No Limits at All

Theological Letters

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Can God make a rock so large that he cannot lift it? This may sound like a joke, but it is actually a profound question because it asks whether the concept of an all-powerful being—God—makes logical sense or reduces to nonsense. The question accomplishes this by creating a conundrum. On the one hand, if God is all-powerful, one ought to be able to affirm any task asked of him: “Yes, he can do that; he is God, and he is all-powerful.” Therefore, if asked whether he can make such a rock, the answer should be yes. On the other hand, affirming this creates a logical trap, for it simultaneously posits something else he cannot do: namely, lift the rock. Is there an answer to this sort of question? Indeed, there is. The answer is no. To understand how we arrive at that answer, we must examine the term in question: omnipotent.

Many people, upon hearing questions like “Can God make a square circle?” or “Can he make free creatures that are not free?”, instinctively think that because he is God, he can do anything. To them, the proposition is irrelevant; God can accomplish anything one might suggest. This is what they assume omnipotence means. However, classical Christianity does not define omnipotence in this way. Omnipotence does not simply mean that God can perform whatever action might be described by a random string of words. What, then, does it mean? While omnipotence does mean that God can do anything, this position includes the qualification that not every combination of words actually describes a “thing.” In other words, contradictions are contradictions, even for God.

Realism, Nominalism, and the Order of Reality

To understand where this concept originates, we must explore a philosophical position known as realism.¹ Realism centers on a fundamental observation: every rational being, from the moment a child begins to speak, reasons in terms of groups. We think in terms of genera (animal), species (dog), and common properties (bipedal). As Porphyry summarizes the question of realism, we must ask whether genera and species exist in themselves or reside in mere concepts alone.² We all do it, but why? The realist answers that the mind does this because these groups are real; they reflect the actual structure of reality.

The alternative to this view suggests that the world is not inherently structured. Instead, reality is merely chaotic matter in motion, lacking inherent organization because organization requires a mind. Therefore, these groups and structures are not features of reality itself; they are efforts of the human mind to organize its experiences. They are simply names or mental fictions invented to categorize the external world. If one argues that logic, mathematics, and rational structures are mere mental fictions, that person is a nominalist—derived from the Latin nomen, meaning name. They believe these categories are just names projected onto reality, not reflections of reality itself.

Christianity has historically aligned with the realist tradition. Realism appears very early in pagan philosophy, with initial forms emerging among the Pythagoreans, such as Pythagoras (c. 570–c. 495 BC). The most prominent forms of realism are found in Plato (c. 428–348 BC) and Aristotle (384–322 BC). Plato argued that our world is a material copy of an ideal world constructed of perfect archetypes or forms.³ This is known as extreme realism, as it posits that these structures not only are real but comprise an independent realm. In contrast, the moderate realism of Aristotle argues that these structures are real but exist immanently within matter, providing structure much like DNA drives the development of an organism.⁴ Between these two, Middle Platonists and Neoplatonists argued that archetypal blueprints pre-exist the world within the mind of God, who then imparts this structure to matter. This hybrid of Platonic and Aristotelian thought represents the realist tradition to which early Christians belonged.

This alignment is unsurprising, as most ancient thinkers who believed in providence—the idea that the world originates from a divine mind—tended to be realists. The providentialist position asserts that mind precedes matter, and this mind (God) produces the material world. Therefore, the rational structures we observe in the world are simply reflections of the divine mind that gave rise to them. When our minds examine the world, we recognize these inherent patterns and structures.

This view contrasts sharply with the Epicureans, who were early materialists. They believed reality consisted solely of chaotic matter in motion, with mind emerging as a secondary byproduct that invents fictions to project onto this chaos. These early proto-nominalists were fundamentally opposed to the Christian providentialists. Christian realism was uniquely informed by the biblical text. For example, in the book of Genesis, God says, “Let us make,” and then names the things he intends to create before they exist (Gen 1:26). Early interpreters naturally asked what God was referring to, concluding that he must possess an idea of what he intends to make. Thus, Alexandrian Jewish thinkers like Philo of Alexandria⁵ and Christian theologians like Origen of Alexandria⁶ utilized analogies comparing God to an architect holding a blueprint before building a city. Being rational, God possesses archetypal ideas (logoi) that serve as the blueprint for creation. He creates matter and imparts structure to it—a structure reflective of those divine ideas.

The significance of this realist commitment is that if logic reveals the order of reality itself, then a logical contradiction—something that is logically nonsense—is not merely impossible in the realm of human thought; it is impossible per se. Contradictions are not just contradictions for human beings; they are contradictions inherently. Put more strongly, contradictions are contradictions even for God.

Historically, certain thinkers have been uncomfortable with this conclusion. This tension emerged clearly in late medieval scholasticism. It was relatively standard in earlier scholasticism to assert that whatever implies contradiction is beyond the bounds of omnipotence. However, later figures like William of Ockham (c. 1287–1347) bristled at the notion that God “cannot” do something. They pietistically pushed back against realism, suggesting that these rational structures and contradictions apply only to us, not to God, who transcends such limitations. Consequently, they advocated nominalism, arguing that logic and reason are merely human inventions for organizing experience, rather than indicators of reality itself.⁷

The Arian Dispute and Metaphysical Necessity

This nominalist position was innovative relative to Christian history and was frequently viewed with suspicion, often bordering on heresy. Realism was not merely a popular philosophical preference among early Christians; it was foundational to their understanding of core Christian doctrines. This is most evident in the Arian dispute, an early ecumenical crisis that necessitated the Council of Nicaea to adjudicate the boundaries of the received faith.

Arius of Alexandria (c. 256–336 AD) taught that the Son of God is a creature. According to Arius, God the Father existed alone before deciding to have a Son, leading him to create a godlike being called, by analogy, the Son of God. The telltale sign of Arianism was the phrase “there was when he was not,” asserting a time when the Son did not exist.⁸ This dispute, which produced the first draft of the Nicene Creed, demonstrates that early Christians viewed realism as a confessional element of Christianity.

When Arius espoused his heresy, the pro-Nicenes—defenders of traditional orthodoxy such as Athanasius of Alexandria (c. 296–373 AD) and Alexander of Alexandria (d. 326 AD)—responded by pointing out the logical entailments of Arius’s claim. They argued that if the Son is created, he is necessarily changeable, corruptible, and only accidentally good.⁹ These charges reflect a realist conviction: the fathers were not suggesting that creatures happen to be changeable, but that it is a metaphysical necessity.¹⁰ To be created is to be mutable; not even God can create a second God. They argued that these traits are necessary logical entailments of creaturehood, and this structure of reality applies even to God.

This point was solidified when Arius attempted to modify his position. To counter the charge of mutability, Arius suggested that God created the Son unlike other creatures, making him unchangeable and immutable.¹¹ The pro-Nicene response was that such a proposition is not just false; it is nonsense.¹² Eastern Christian hymnody praises Athanasius for refuting the “heretical nonsense” of Arius. Why did they view it as nonsense? They recognized an inherent contradiction: to be created is to come into being, which is the very definition of change.¹³ One becomes something they previously were not. For Arius to claim that God causes something to come into being, yet that thing is entirely unchangeable, is a formal contradiction. The response was that not even God can do that; not even God can create a second God. The Nicene discussion demonstrates a firm commitment to the idea that contradictions are contradictions even for God.

Nonsense Remains Nonsense Even for God

Some may still bristle at the phrase “God cannot,” feeling that it undermines divine omnipotence. The common pietistic instinct is to assert that God can do anything, including making free creatures that are not free or creating square circles. However, examining this impulse requires asking a few fundamental questions.

First, can God lie? A Bible-believing Christian will recall the Epistle of James, which states that God cannot lie (cf. Jas 1:17; Titus 1:2; Heb 6:18). Is James speaking blasphemy, or is it true that lying is logically and fundamentally incompatible with the nature of God?

Second, can God simply stop existing? The immediate theological inclination is to say no, God cannot cease to exist. By affirming this, one is acknowledging that there is something about the nature of God that entails existence, making non-existence completely incompatible with his nature.

Third, can God create a second God? As demonstrated by the pro-Nicenes in the Arian dispute, being created and being God are fundamentally incompatible concepts. Not even God can create a second God. These instincts—recognizing that God and lying, being created and being God, or God and non-existence are contradictory—are realist instincts. They affirm that certain concepts cannot be combined because they contradict each other inherently.

If one still feels uncomfortable saying “God cannot” make a free creature that is not free, or a square circle, it likely stems from a misunderstanding of what is actually being said. When people hear that God cannot make a free creature that is not free, they imagine an exceedingly complex or bizarre entity that is simply beyond God’s power to produce. This misrepresents the classical Christian position on omnipotence.

The limitation being indicted is not God’s power, but the coherence of the language being used. To say that God can do something requires presenting an actual “something.” Stringing together incompatible words does not create a meaningful proposition. The phrase “a free creature that is not free” is not a description of a difficult task; it is a nonsensical linguistic absurdity. It is an empty noise. The same applies to a “square circle.” As Thomas Aquinas (1225–1274) explicitly stated, whatever implies contradiction is beyond even omnipotence.¹⁴ Similarly, C.S. Lewis noted that nonsense remains nonsense even when we talk about God.¹⁵ Prefixing a meaningless phrase with “God can” does not suddenly endow it with meaning. The string of words does not rise to the level of a “thing”.

Therefore, when evaluating whether God can make free creatures that are not free, or square circles, or a rock too heavy to lift, the key is not to question God’s power. The necessary scrutiny is whether the proposition describes a coherent concept. When a formal contradiction is identified, it becomes clear that the proposal does not rise to the level of a “thing.” God cannot do it, not because the task is too difficult, but because it is a string of meaningless words.

When asked if God can make free creatures that are not free, the contradiction is obvious: one has combined “A” and “not A.” What about a square circle? One is asking if God can make a two-dimensional shape with a flowing circumference where all points are equidistant from the center, yet simultaneously possessing four sides of equal length and four right angles. The words are understandable individually, but combined, they are nonsense. Consequently, the question of whether God can make a rock so heavy that he cannot lift it is equally flawed. It asks whether a being whose power cannot be exceeded can create an object that exceeds his power. Because this is a formal contradiction, the answer is no. A coherent task has not been proposed in the first place. You haven’t given God anything to do.

1. For an overview of realism, see Frederick Copleston, “The Problem of Universals,” in History of Philosophy, Vol. II: Augustine-Scotus, 9 vols. (Mahwah: Paulist Press, 1950), vol. 2, 136-55.

2. Porphyry, Isagoge, 27-8.

3. Plato’s theory of the Forms is most famously espoused in The Republic, 506d-21b, yet the theory is also present in his arguments for recollection and the immortality of the soul in both Meno and Phaedo.

4. Aristotle, De anima, 412a1-4a28; Metaphysica, 1013a26-8.

5. Philo of Alexandria, De opificio mundi, 16-20.

6. Origen, Commentaria in Euangelium Ioannis, 1.22.

7. William of Ockham, Summa logicae, I.15; Quodlibeta septem, VI, q. 6.

8. Socrates Scholasticus, Historia ecclesiastica, 1.5.

9. Athanasius, De Incarnatione, 3; Alexander of Alexandria, Epistula ad Alexandrum Constantinopolitanum, 11-13.

10. Athanasius, Orationes tres adversus Arianos, 1.18.

11. Arius, Epistola ad Alexandrum papam.

12. Athanasius, Epistula ad Serapionem.

13. Aristotle, Physica, 192a25-33.

14. Aquinas, Summa Theologiae, Ia q.25 a.4.

15. C.S. Lewis, The Problem of Pain, 18.