The God of the Gaps

Imagine living three thousand years ago. The sky suddenly splits with light and a sound loud enough to shake your chest. A tree bursts into flames. No one around you knows about electric charge, and no one will for a very long time. What explanation is available?

In many ancient cultures the answer was a god. Zeus threw thunderbolts. The sun crossed the sky because a divine being carried or drove it. Illness was punishment, possession or divine displeasure. These were not foolish answers. They were attempts to explain powerful events by the only kind of cause people knew for certain produced things on purpose: an agent with a will.

Then the explanations began to change. Over centuries, lightning, the sun, the tides and many diseases were explained by natural causes. Each time, a place where people had pointed to divine action was filled by something else.

This pattern gave its name to a style of argument that is still very much alive: the god of the gaps. The idea is to point to something science has not yet explained and conclude that God must be the explanation. Critics, including many religious thinkers, argue that this commits believers to an ever-receding god, one who has to step back each time knowledge moves forward.

The criticism concerns a style of reasoning, not religion as a whole. Its history also includes believers who rejected the argument precisely because they thought it made faith depend on ignorance.

The Pattern in History

Early naturalistic explanations

Some of the earliest recorded challenges to divine explanations came from ancient Greece.

Around 400 BCE, a medical treatise in the Hippocratic collection took on epilepsy, then called "the sacred disease." Its author, traditionally identified as Hippocrates but actually unknown, argued that the illness was no more divine than any other disease and had a natural cause. People called it sacred, the author suggested, because they did not understand it. ^[1] The treatise even accused the healers who promoted the divine label of using it to excuse their failures. The argument pattern is the reverse of the god of the gaps: our ignorance does not make something divine.

A few decades earlier, the philosopher Anaxagoras claimed that the sun, traditionally regarded as a god, was a red-hot stone. He was charged with impiety and left Athens. ^[2] More broadly, the early Greek philosophers now called the Presocratics tried to explain the world through natural principles such as water, air or opposing forces, instead of stories about gods. ^[3]

These examples should not be overstated. Ancient societies did not simply move from "gods" to "science" in a straight line, and many ancient thinkers combined natural explanations with religious belief. But they show that the question of whether an unexplained event requires a divine cause is very old.

Later examples

Over the following two millennia, many phenomena once linked to divine action received natural explanations:

• Lightning was shown in the eighteenth century to be an electrical discharge.
• Tides were explained by Newton's theory of gravity, later refined by Laplace to include the rotation of the Earth. ^[4]
• Many diseases came to be explained by microorganisms, nutrition and genetics.

None of these discoveries disproved God. What they did was remove specific jobs that had been assigned to God.

Newton, the Planets and Laplace

The best-known case involves Isaac Newton, one of the greatest scientists in history and a deeply religious man.

What Newton claimed

Newton's law of gravity explained why planets move in ellipses around the Sun. But it raised two puzzles that he did not think gravity alone could solve.

First, all the planets orbit in the same direction and nearly the same plane. In his letters to the theologian Richard Bentley in the 1690s, Newton argued that gravity alone could never have produced such an orderly arrangement. He concluded that it required the intention of an intelligent agent. ^[5] In the General Scholium added to later editions of his Principia, he wrote that this beautiful system could only have come from the counsel and dominion of an intelligent and powerful being. ^[6]

Second, the planets pull on each other, not only on the Sun. Newton worried that these small interactions would build up over time. In his Opticks he suggested that small irregularities would tend to grow until the system needed to be put right again, a "reformation." ^[7] Many readers took this to mean that God occasionally intervened to keep the solar system stable. ^[8]

Leibniz's objection

Interestingly, the sharpest early criticism came not from an atheist but from another religious philosopher. In his correspondence with Newton's defender Samuel Clarke in 1715–1716, Gottfried Wilhelm Leibniz mocked the idea. On Newton's view, he said, God's watch would stop unless God rewound it from time to time, as if God lacked the foresight to build it properly in the first place. ^[9]

Leibniz's point was theological. A perfect creator, he argued, would make a world that ran according to its own laws without needing repairs. Divine repair work implied divine incompetence. This is an early and clear version of the modern critique: using God to patch holes in a theory can make God smaller, not greater.

Laplace's answer

A century later, Pierre-Simon Laplace and other mathematicians developed much more precise methods for calculating how planets disturb one another. Laplace showed that the average orbital motions of the planets remain stable over very long periods, with apparent irregularities, such as a long cycle in the motions of Jupiter and Saturn, turning out to be periodic effects of gravity itself. ^[4,10]

A famous anecdote has Napoleon remarking that Laplace's great book on the heavens never mentioned God, and Laplace replying that he had had no need of that hypothesis. ^[11] The story comes to us through later retellings, and its exact wording is uncertain. Historians also disagree about what Laplace meant. A common interpretation is that he was making a scientific point, not announcing atheism: his equations no longer needed divine intervention to keep the planets on course.

The twist

The story did not end with Laplace. In 1989 the astronomer Jacques Laskar showed through numerical calculations that the solar system's long-term motion is chaotic: tiny differences in starting conditions grow exponentially, making detailed prediction impossible beyond a few tens of millions of years. ^[12] Later work found a small chance, around one percent in their simulations, that Mercury's orbit could become unstable within the next five billion years. ^[13]

This does not bring back Newton's argument. The solar system is chaotic, but the instability happens on timescales of billions of years and follows from gravity alone. It does show that the history of science is not a simple series of gaps closing neatly. Sometimes a gap closes, and the answer turns out to be stranger than either side expected.

Naming the Argument

Henry Drummond, 1894

The phrase grew out of lectures by the Scottish evangelical writer and scientist Henry Drummond. In The Ascent of Man (1894), Drummond, a Christian who accepted evolution, criticised "reverent minds" who searched nature and science for gaps they could fill with God. His objection was pointed: "As if God lived in gaps?" ^[14]

Drummond's worry was practical. If God is found only where knowledge fails, what happens to faith when the gaps are filled? And if they are never filled, is God to be found only in the disorders of the world? ^[14] He argued that God should be seen in the whole of nature, including what science explains.

Dietrich Bonhoeffer, 1944

The German Lutheran pastor and theologian Dietrich Bonhoeffer developed the same idea while imprisoned by the Nazi regime, shortly before his execution in 1945. In a letter to his friend Eberhard Bethge dated 29 May 1944, he warned against using God as a stopgap for the incompleteness of human knowledge. If God is placed at the boundaries of knowledge, he wrote, God will be pushed back as those boundaries advance. God should be found in what we know, not in what we do not. ^[15]

Bonhoeffer's letters connect this to a larger theme: a world that has "come of age" and no longer needs God as an explanation for everyday events. He did not conclude that God was unnecessary. He concluded that faith should not depend on human ignorance.

Charles Coulson, 1955

The Oxford mathematician and theoretical chemist Charles A. Coulson, a committed Methodist, made the phrase "God of the gaps" widely known in Science and Christian Belief (1955). ^[16] His argument was that gaps in scientific knowledge tend to shrink, so a God found only in those gaps is a God in retreat. Coulson's alternative, like Drummond's, was that God is either present in the whole of nature, including what science explains, or not present at all.

It is worth noticing that all three writers who shaped the concept were Christians. The critique of god-of-the-gaps reasoning began largely inside religious thought.

How the Argument Works

The god-of-the-gaps argument usually has this shape:

1. Phenomenon X has no known natural explanation.
2. Therefore, X was caused by God.

In this simple form, the argument is an argument from ignorance (Latin argumentum ad ignorantiam). This fallacy takes the lack of evidence against a claim as if it were evidence for it. ^[17] Not knowing how X happened is not the same as knowing that God did it. The honest conclusion from step 1 is "we do not know yet."

A useful comparison: a detective who cannot identify a burglar is not entitled to conclude that the burglar was a particular suspect with no evidence connecting them to the crime. The lack of another explanation does not by itself point to any specific answer.

Why the god "recedes"

The argument has a second weakness that is not purely logical. It ties belief to the current state of science. Each time a gap closes, the argument loses ground, and the believer who relied on it must either give up that belief or move to a new gap. Over centuries this produces the pattern of retreat described by Drummond, Bonhoeffer and Coulson.

This is the core of the "ever-receding god" problem. A god defined by what we do not understand becomes smaller as understanding grows. Religious critics find this theologically damaging, because it makes God one more cause among others, competing with gravity and genetics instead of being the ground of everything.

A fair qualification

Not every argument that mentions a gap is a fallacy. Philosophers of religion point out that whether nature contains real causal gaps is, in principle, an empirical question, not something to be ruled out in advance. ^[18] An argument can also claim more than ignorance. It can claim that a known feature of the world is better explained by design than by any available alternative. That is an inference to the best explanation, not a pure appeal to ignorance.

Such arguments can still fail. They can be defeated by new natural explanations, and they carry the burden of showing why design is actually the best explanation. But it is not accurate to dismiss every argument for God as a god-of-the-gaps argument. Critics sometimes use the label loosely, as an insult, rather than as a precise charge. ^[18]

The Modern Frontier: Before the Big Bang

Today the most visible gaps are at the edges of physics and biology. The observable universe has been expanding for about 13.8 billion years, according to measurements of the cosmic microwave background. ^[19] What, if anything, came "before" that early hot, dense state is unknown. Some models suggest the question has no meaning because time itself began. Others propose earlier phases, such as a bounce from a previous contracting universe. None of these proposals has been confirmed. ^[20]

A similar gap exists for the origin of life: researchers have plausible partial pathways, but no complete, demonstrated account of how the first living systems arose.

It is common to hear "science can't explain what came before the Big Bang, so God must have done it." In that form, the argument has exactly the gap structure described above, and it faces the same risk: if physics develops a well-supported account of the earliest universe, the argument loses its footing.

Physics does not currently answer this question either. The honest scientific statement is: we do not know. That includes not knowing that the answer is natural, as well as not knowing that it is divine.

How Many Believers Avoid the Gap

Many theologians and philosophers of religion reject god-of-the-gaps reasoning and ground belief in God differently. The following positions are described neutrally. Each has defenders and critics, and none is presented here as correct or refuted.

Classical theism

In the tradition associated with Thomas Aquinas, God is not one cause among others in nature, competing with physical causes. God is the reason anything exists at all and the source of the whole order of causes. ^[21] On this view, natural science explains how things work within the world, while God explains why there is a world with causes at all. A complete physics would not remove God, because God was never meant to fill a gap inside physics.

Critics reply that this makes God's existence hard to test and ask whether the concept of a first cause or necessary being is coherent. Those debates are active in philosophy.

Cosmological arguments

Cosmological arguments begin not from a particular unexplained event but from the existence of the universe itself, or its dependence on something beyond it. Some versions argue from contingency: why is there something rather than nothing? Others, such as the kalām argument, argue that the universe began to exist and therefore has a cause. ^[22] Some theists have seen Big Bang cosmology as support for a beginning, while others caution that tying theology to a particular cosmological model repeats the gap mistake at a larger scale. ^[20]

Fine-tuning

Physicists have noted that some constants of nature appear to fall within narrow ranges compatible with life. Some philosophers argue that this is better explained by design than by chance. ^[23] Others respond that it could be explained by a multiverse, by a deeper physical theory that fixes the constants, or by the observation that we could only find ourselves in a life-permitting universe. The argument is debated as a matter of probability and explanation, and it is not simply a gap argument, although critics note that it could weaken if a deeper theory explained the constants. ^[23] See also Determinism and the Block Universe for related questions about how physical law frames explanation.

Faith not based on argument

Many believers do not base their faith on any argument about nature. They cite personal experience, religious tradition, revelation or community life. For them, the success or failure of gap arguments is largely beside the point. The broad field of religion and science includes positions that see conflict, independence, dialogue or integration between the two. ^[24]

Limitations and Open Questions

• Historical simplification: the story "gods explained nature, then science replaced them" is a simplification. Many major scientists, Newton among them, were religious, and many religious traditions encouraged the study of nature.
• The limits of the critique: showing that one argument is weak does not show that its conclusion is false. The god-of-the-gaps critique undermines a way of reasoning. It does not, by itself, prove or disprove God's existence.
• Science's own limits: some questions, such as why the laws of physics exist at all, may lie outside what empirical science can answer. Whether that leaves room for theological answers, or only for honest uncertainty, is a philosophical question.
• Loose use of the label: the term is sometimes applied to careful arguments that do not rely merely on ignorance. Each argument must be judged on its own structure.

Where Belief Can Stand

The god of the gaps is a lesson about the relation between knowledge and belief. Linking the divine to whatever is currently unexplained has a poor historical record. Lightning, the sun, disease and planetary stability were all once explained by divine action and later explained naturally.

The historical pattern is real, and religious thinkers from Leibniz to Drummond, Bonhoeffer and Coulson recognized the danger themselves. The critique establishes one narrow point: ignorance is not evidence, so an unexplained event does not by itself identify God or any other cause. It leaves untouched the deeper question these writers were asking—whether belief can rest somewhere other than the edges of knowledge. Closing, or failing to close, any single gap cannot settle that.

References

[1] Hippocrates (attrib.); Adams, F. (trans.). (1849). "On the Sacred Disease." The Internet Classics Archive, MIT.
http://classics.mit.edu/Hippocrates/sacred.html

[2] Sisko, J., & Curd, P. (2007, rev. 2026). "Anaxagoras." Stanford Encyclopedia of Philosophy.
https://plato.stanford.edu/entries/anaxagoras/

[3] Curd, P. (2007, rev. 2020). "Presocratic Philosophy." Stanford Encyclopedia of Philosophy.
https://plato.stanford.edu/entries/presocratics/

[4] Smith, G. E. (2007). "Isaac Newton." Stanford Encyclopedia of Philosophy.
https://plato.stanford.edu/entries/newton/

[5] Newton, I. (1692–1693). Original letter from Isaac Newton to Richard Bentley. The Newton Project, University of Oxford.
https://www.newtonproject.ox.ac.uk/view/texts/normalized/THEM00258

[6] Newton, I.; Motte, A. (trans.). (1729). "General Scholium," from The Mathematical Principles of Natural Philosophy. The Newton Project, University of Oxford.
https://www.newtonproject.ox.ac.uk/view/texts/normalized/NATP00056

[7] Newton, I. (1730). Opticks (4th ed.), Query 31. Project Gutenberg.
https://www.gutenberg.org/ebooks/33504

[8] Janiak, A. (2006, rev. 2021). "Newton's Philosophy." Stanford Encyclopedia of Philosophy.
https://plato.stanford.edu/entries/newton-philosophy/

[9] Leibniz, G. W., & Clarke, S. (1715–1716); Bennett, J. (ed.). (2017). Exchange of Papers between Leibniz and Clarke. Early Modern Texts.
https://www.earlymoderntexts.com/assets/pdfs/leibniz1715_1.pdf

[10] O'Connor, J. J., & Robertson, E. F. (1999). "Pierre-Simon Laplace." MacTutor History of Mathematics Archive, University of St Andrews.
https://mathshistory.st-andrews.ac.uk/Biographies/Laplace/

[11] O'Connor, J. J., & Robertson, E. F. "Quotations by Pierre-Simon Laplace" (citing A. De Morgan, A Budget of Paradoxes). MacTutor History of Mathematics Archive, University of St Andrews.
https://mathshistory.st-andrews.ac.uk/Biographies/Laplace/quotations/

[12] Laskar, J. (1989). "A Numerical Experiment on the Chaotic Behaviour of the Solar System." Nature, 338(6212), 237–238.
https://doi.org/10.1038/338237a0

[13] Laskar, J., & Gastineau, M. (2009). "Existence of Collisional Trajectories of Mercury, Mars and Venus with the Earth." Nature, 459(7248), 817–819.
https://doi.org/10.1038/nature08096

[14] Drummond, H. (1894). The Lowell Lectures on the Ascent of Man. Christian Classics Ethereal Library.
https://www.ccel.org/ccel/d/drummond/ascent/cache/ascent.pdf

[15] Bonhoeffer, D.; de Gruchy, J. W. (ed.); Best, I., Dahill, L. E., Krauss, R., & Lukens, N. (trans.). (2010). Letters and Papers from Prison. Dietrich Bonhoeffer Works, Vol. 8. Fortress Press.
https://www.fortresspress.com/store/product/9780800697037/Letters-and-Papers-from-Prison

[16] Coulson, C. A. (1955). Science and Christian Belief. Oxford University Press (Collins reprint, 1961). Internet Archive.
https://archive.org/details/sciencechristian0000coul

[17] Dowden, B. "Fallacies" (entry "Appeal to Ignorance"). Internet Encyclopedia of Philosophy.
https://iep.utm.edu/fallacy/

[18] Ratzsch, D., & Koperski, J. (2005, rev. 2023). "Teleological Arguments for God's Existence." Stanford Encyclopedia of Philosophy.
https://plato.stanford.edu/entries/teleological-arguments/

[19] Planck Collaboration: Aghanim, N., Akrami, Y., Ashdown, M., et al. (2020). "Planck 2018 Results. VI. Cosmological Parameters." Astronomy & Astrophysics, 641, A6.
https://doi.org/10.1051/0004-6361/201833910

[20] Halvorson, H., & Kragh, H. (2011, rev. 2021). "Cosmology and Theology." Stanford Encyclopedia of Philosophy.
https://plato.stanford.edu/entries/cosmology-theology/

[21] Pasnau, R. (2022). "Thomas Aquinas." Stanford Encyclopedia of Philosophy.
https://plato.stanford.edu/entries/aquinas/

[22] Reichenbach, B. (2004, rev. 2026). "Cosmological Argument." Stanford Encyclopedia of Philosophy.
https://plato.stanford.edu/entries/cosmological-argument/

[23] Friederich, S. (2017, rev. 2026). "Fine-Tuning." Stanford Encyclopedia of Philosophy.
https://plato.stanford.edu/entries/fine-tuning/

[24] De Cruz, H. (2017, rev. 2022). "Religion and Science." Stanford Encyclopedia of Philosophy.
https://plato.stanford.edu/entries/religion-science/