God of the Gaps

Then there is the phrase "The God of the Gaps"™.  In any long discussion on "Science and Religion", this phrase must eventually be deployed by one or the other party, either by the skeptic (with a triumphal tone as of one finally deploying his most powerful weapon) or else by the articulate and educated defender of a modern faith, showing his sophisticated ability to rise above primitive superstitions: "But that's the God of the Gaps™!" they say in response to a proposed act of the Deity, "We can't possibly believe in that!"

In the debate between Carroll and St. Craig, both participants had their obligatory five seconds of hate towards this idea.  Craig:

This is not to make some sort of naïve claim that contemporary cosmology proves the existence of God. There is no God-of-the-gaps reasoning here. Rather I’m saying that contemporary cosmology provides significant evidence in support of premises in philosophical arguments for conclusions having theological significance.


It is certainly a true issue that we don’t know why the early universe had a low entropy and entropy has ever been increasing. That’s a good challenge for cosmology. To imagine the cosmologist cannot answer that question without somehow invoking God is a classic god-of-the-gaps move. I know that Dr. Craig says that is not what he’s doing but then he does it.

It is difficult to fight against a slogan delivered so frequently and with such conviction, especially when for some perverse reason educated and intelligent people on both sides insist on attacking the same strawman.  But it is worth pointing out, that if the detractors of an idea could be defeat it simply by labeling it with a silly-sounding alliterative phrase, we wouldn't be able to believe in the “Big Bang” theory either.

As Carroll quotes the philosopher David Lewis as saying:

I do not know how to refute an incredulous stare.

These references to the God of the Gaps™ often function as a similar incredulous stare, not any kind of actual argument.  (Mind you, the incredulous stares Lewis got were because of his belief in modal realism, i.e. every single logically possible world is equally real.  Perhaps those incredulous stares just meant that ideas which flagrantly violate common sense should be assigned a tiny prior probability?)

Anyway, if the God of the Gaps™ is a fallacy, it's a very strange one.  It is not any one of the standard textbook logical fallacies, and it is only ever brought up in theological contexts.   On the surface, it sounds awfully like claiming that inference to the best explanation is a fallacy.  Let me pull out some home truths here, and make the following bold statement:

Any time we ever believe in anything rationally, we do so because there is some kind of "gap" in our understanding of how the universe works, which is filled by postulating the existence of that thing.

In other words, all valid arguments that something exists are based on Of-the-Gaps type reasoning.  This is just how reasoning (scientific or otherwise) works.

This is not to say, of course, that all gaps are best filled by postulating specific divine intervention.  Of course not.  Admittedly, Monotheists do believe the following:

All phenomena which occur in Nature do so because God sustains the world in being, thus (at least indirectly) causing everything.

But this hardly implies that all phenomena make equally good evidence for God's existence.

To the best of my knowledge, no Christian apologist has ever made the following argument: 1) Science cannot explain high temperature superconductivity [a puzzling phenomenon in condensed matter physics], 2) therefore an intelligent designer must have caused it, 3) therefore God exists.  The reason is that it is obvious in this case that there should exist in principle an ordinary scientific explanation for this phenomenon.  Superconductors involve complicated, messy physics and there is no particularly good reason to be surprised that we don't understand them fully yet.

(When an Intelligent Design theorist such as St. Behe argues that: 1) there exist phenomena in Nature such as bacterial flagellum which could not plausibly have evolved naturally because they have irreducible complexity, 2) therefore they must have been created by an intelligent designer, he is not committing any type of logical fallacy, let alone God of the Gaps™.  The problem with his argument is that biologists have shown that his premise (1) is false, but it's a perfectly good type of argument, if its premises were really true.)

In other cases, such as the seeming low-entropy beginning of the Universe, or the fine-tuning of the constants of Nature to permit life, or why certain forms of life have conscious experiences, or why murder is wrong, or for that matter why there is a material Universe at all, it is at the very least not completely obvious that there will exist a natural explanation of the usual scientific type.  There is a reason that theistic philosophers (not being totally stupid) latch onto these types of "big" or "fundamental" questions rather than questions about superconductivity.

It's actually the exact same reason why many atheistic philosophers will deny that these are meaningful questions to which one has a right to expect an answer.  (Carroll does this in the debate, regarding the question of why the Universe came into existence.  Assuming for the sake of argument that it did, he argues that this is not the sort of thing one needs an explanation for.)  One could imagine a hypothetical physics which is in one sense a complete system of equations, and yet fails to answer some or all of these questions.  In that case the Naturalist will (because of his conviction that Science is the only ultimate path to truth) deny that the questions are meaningful, while any person who feels unable to swallow this will have for themselves an argument for the existence of God.

Other, more optimistic Naturalists may hold to the belief that "Science will one day explain that".  Since data about what Science will do in the future is sadly unobtainable, this type typically appeals to one of those historical just-so stories I mentioned in my previous post.  To rephrase it once more (note that I do not accuse Carroll of making the following argument in all particulars; as I said I am using the debate as a springboard to talk about larger issues):

"Our superstitious ancestors thought that nearly all natural phenomena—the rising of the sun, the growth of the crops, etc. were attributable to numerous supernatural beings. Science has discredited nearly all of these ideas, but of course Science is not yet complete. The modern day defenders of religious traditions, therefore, although their original motivation for belief is gone, cling to these holes in our understanding as keeping a place for the divine activity. If only evolution or Big Bang cosmology or something leaves a place for God's activity, these religious types argue, then we have some role for Religion. But as Science continues to discover more and more, the gaps get smaller and smaller, and eventually these claims will disappear as well. To cling to this sort of Religion is worthless."

This type of reasoning (which is quite common, although I phrase it in my own words) tends to glide imperceptibly from popular pagan polytheists (who thought there was a divinity for every major or minor phenomenon) to the Hebrew monotheists (who resisted this trend as superstitious and wrong).

It was perfectly obvious to any pagan philosopher or early Christian that Nature proceeds according to orderly laws, and natural processes. Modern Science can take credit for unifying the description of many phenomena into common mathematical frameworks, but to act as though the existence of order in Nature is a modern discovery is simply absurd. It is true that this fact is in considerable tension with certain forms of Animism or Nature Polytheism. But certainly almost any astute monotheist living in the last two thousand years, is going to admit that God causes most things to happen, not through whim but through the operation of certain natural processes, which can be understood to some extent by human reason.

In this sense, Naturalism and Monotheism have a shared (and highly successful) common heritage.  Both of them imply that the material world is not to be understood as divine, and that therefore it is fair game for impersonal study and observation.  To act as though the fruits of this shared common presupposition is some type of falsification of one of these two positions is completely unfair.

So then, everyone should stop using this phrase, God of the Gaps™.  In addition to being confusing and condescending, and not really a logical fallacy, it almost always indicates the presence of a strawman opponent.  Very few religious people believe that God exists only to fill gaps in our understanding of Science.  Let's argue against the real positions on the table.

About Aron Wall

I am a Lecturer in Theoretical Physics at the University of Cambridge. Before that, I read Great Books at St. John's College (Santa Fe), got my physics Ph.D. from U Maryland, and did my postdocs at UC Santa Barbara, the Institute for Advanced Study in Princeton, and Stanford. The views expressed on this blog are my own, and should not be attributed to any of these fine institutions.
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15 Responses to God of the Gaps

  1. Ashley says:

    This might be my favorite entry so yours so far. I wonder especially about what you highlight about the Naturalist's denial of meaningful 'big questions". Why do you suppose some people 'swallow' that denial so easily while many of us cannot? Is there a rational motivation for that?

  2. Mark says:


    I'm really enjoying the new series of posts. Stephen C. Meyer has a good discussion of the god-of-the-gaps™ criticism in his book, Signature in the Cell. He notes that if the argument in question takes the following form:

    Premise One: Cause X cannot produce or explain evidence E.
    Conclusion: Cause Y produced or explains E.

    then it would be commiting the argument from ignorance fallacy. What needs to be included in addition to negative evidence against an alternative cause is a premise offering positive support for the conclusion. So he would structure his 'inference to the best explanation' argument in the following way:

    Premise One: Despite a thorough search, no material causes have been discovered that demonstrate the power to produce large amounts of specified information.
    Premise Two: Intelligent causes have demonstrated the power to produce large amounts of specified information.
    Conclusion: Intelligent design constitutes the best, most causally adequate, explanation for the information in the cell.

  3. Mark says:

    *Or maybe another way of phrasing Premise Two would be: In our uniform and repeated experience, intelligent causes are the only known source of large amounts of specified functional information.

  4. Aron Wall says:


    Thanks for your comments. Obviously, in order to make an inference to the best explanation, we need to consider all possible explanations, before deciding which one is best. What makes this hard is that we need to include explanations like "some scientific theory of type X we haven't thought of yet". Obviously we can't assess the likelihood of this in detail, but we can at least get some gut sense of how plausible it is, depending on the nature of the specific question.

    Like the arguments of St. Behe, the ID argument you present is valid, but one of the premises is not true: namely that no material causes have the power to produce large amounts of "specified complexity".

    This argument sounds like it is based on the arguments of St. Dembski on "specified complexity". Unfortunately, Dembski is, in fact a crackpot. At least, I am a physicist who uses information theory in my work, and I find many of his claims about probability to be incomprehensible, meaningless, or wrong. There are many criticisms of this concept available on the web, e.g. here or here.

    For any reasonable definition of complexity, there are lots of unintelligent physical processes which can produce it. Darwinian evolution being just one example.

  5. Aron Wall says:


    That's an interesting question. Obviously part of the appeal of Naturalism is its simplicity. Whereas you or I might say that it is far too improverished to include things like the reality of ethics or qualia), they would say that the Naturalism is a wonderful theory precisely because it rejects all of these squishy unquantifiable things as meaningless, except insofar as they can be reinterpreted as the motion of atoms etc. (I am oversimplifying here, since there is a great deal of disagreement among Naturalists about which things should come under this ban.) Once you accept Naturalism (or any other metaphysical system) you tend to use it as a yardstick to ask which questions are or are not meaningful. But there is a danger here of circular reasoning.

    Ultimately Naturalism (especially in its more eliminative varieties) requires quite a bit of distrust of one's own brain. Our brains have lots of different parts, which tell us about ethics, color, sex, God, causality, and so on. Naturalism claims to be based on the "scientific method"; by this it really means that our evolved faculties are radically unreliable except for very specific parts used in very specific ways.

    Now all of these other parts of their brain are still working to some extent, even without encouragement. Naturalists can and do have mystical experiences, but they discount them. They make ethical judgements, but they think they are just arbitrary statements of cultural preference. They can and do appreciate the deep aesthetic value of Nature---that's why many of them start to study Science in the first place (sometimes, like Carl Sagan, they even turn to it as a substitute source of religious consolation)---but they discount it as evidence (as Carroll did in the debate when he talked about Nature not being an artist). They just don't think that these human faculties tell us anything deep about the world.

    In this respect, the Naturalist is radically alienated from themselves as well as from God. It's easier to find God if you look for him with your whole brain, but they are looking (if at all) with a philosophically truncated split-brain.

  6. Jonathan says:

    Aron, I enjoyed this post very much. Well said.

    I just had a quick question about your reply to Mark's comment. You said that "in order to make an inference to the best explanation, we need to consider all possible explanations, before deciding which one is best." But isn't this too strong of a claim? My impression from talking with defenders of IBE in epistemology is that, as an epistemological position, it only requires considering all available explanations. In order to consider all possible explanations, one would have to know all possible explanations, and it seems to me that we will not often be in a position to know that. A kind of skepticism would follow with respect to those questions for which we don't know what all the possible explanations are, even if we do know what some of the possible explanations are (these known possibilities would be the "available" ones), and one of those is clearly the best of the bunch. Do you think it would be irrational to believe the explanation that was clearly the best of those available when there might be possible explanations of which one is unaware?

    I'm no specialist here, and this is a genuine question, not an attempt to spring a trap. I also realize that this question is getting a bit off the topic of your post, but I thought I'd ask anyway since it occurred to me.

    Thanks again for the post.


  7. Aron Wall says:

    The right thing to do is to estimate the probability that the correct explanation is one you haven't thought of yet. Sometimes this probability is small (when you are reasonably sure you have ennumerated all reasonable possibilites) and sometimes it is large (when dealing with subtle or speculative situations such as quantum gravity). After including "None of the above" as an additional possibility, now you have an exhaustive set of possibilities and the probabilities should add to 1.

    If the probability of "None of the above" is large, then yes, it can be irrational to believe that the best explanation you've thought of so far is right.

    In the case of Evolution, we have to remember that evolutionary biology is a general paradigm which has been highly successful in explaining many specific features of biological systems. There are millions of different facts to explain, so it's not at all surprising that in a few cases we haven't thought of any good evolutionary explanations yet. But a lot of the specific examples, put forward by ID people like St. Behe, have since been given good natural explanations.

  8. Kevin Johnson says:

    Thanks for making a post on this, I have always found this so called "fallacy" to be in itself flawed. Despite being condescending I feel like it's just used to end conversations by making the other argument seem silly and dated (similar to the classic "Santa Claus" argument often employed by atheists).

  9. Aron Wall says:

    I appreciate your comments (and obviously I agree with them).

    While people may ocassionally make reasonable points that are in the vicinity of the "God of the Gaps" objection, the phrase is much too vague by itself to be useful as it stands... it's one of those lazy "thought saving" devices used to avoid the effort of actually making an argument.

    Another thing to note about "God of the Gaps", is that even though it is claimed to be a fallacy, it is only ever used in one particular subject (theology). There is no general "Gaps Fallacy" that people talk about, in other fields of study. That's a huge red flag, because normally fallacies are general patterns of diseased thought which they can pop up almost anywhere. This looks more like a one-time-only pass, good for just for one particular controversy, and that raises the question of why it should be considered a fallacy in the first place.

  10. Mactoul says:

    I think that the God of the Gaps refers to a precise phenomenon e.g. when Newton invoked Divine Assistance to stabilize planetary orbits or when theist physicists invoke God to resolve quantum paradoxes.

  11. Pingback: Le Dieu-des-lacunes est-il un raisonnement fallacieux? – Défense du théisme

  12. Pingback: Fine-Tuning 12: God-of-the-Gaps | Veritas Christo et Ecclesiae

  13. Sam Harper says:

    My impression of the "God of the gaps" complaint is that the person raising the complaint thinks God is being offered arbitrarily to explain something. The argument is that if you see a phenomena, and you don't have any evidence indicating what caused it, then to postulate God as an explanation is just arbitrary. If you wanted to generalize this fallacy, you could just call it the "Arbitrary Cause" fallacy or the "Appeal to Arbitrary Causal Explanation" fallacy. Maybe it already has a name I'm unaware of.

  14. JHB Swart says:

    Hi Aron,

    Love your work, but not really fair to refer to Dembski as a crackpot, others more neutral physicists have defended his work, plus his magnum opus on the subject, was published by Cambridge University Press, he might be wrong of course, but crack pots dont usually get their crack pot theories published by such institutions.

    Also, premise 1 of Behe's argument has never been debunked, instead people have pointed to a sub component that could be used for other purposes, such as injecting toxins, but even evolutionists who specialize in this field, dont for one second think that the flagellum evolved from this pump, rather the other way around, as bacteria would have required propulsion before, plus the type of organisms that is toxin was made for are multicellular organisms that would only have appeared much later.


  15. Aron Wall says:

    JHB Stuart,
    Thanks for the compliment!

    You'd be surprised at how much nonsense can be published by respectable press organizations. You also do not say who you are referring to as "more neutral physicists". As a person who works with information theory in my research, you will have to give me something better than these relatively bland "arguments from authority", in order to convince me that what appears to me to be mathematical gobbledegook and misapplication of theorems is actually rigorous mathematics. Especially since the majority opinion of mathematicians and physicists who have looked at his work is that it is crackpot.

    The central concept in St. Dembski's work, namely "specified complexity", is not a concept that can be given a precise mathematical definition, in the the way other concepts like "von Neumann entropy" or "free energy" or "Kolmogorov complexity" have been defined. In fact he defines the concept in an inconsistent and shifting way depending on the concept. In addition he misapplies "no free lunch" theorems to situations to which their premises are clearly inapplicable. Please read the reviews I linked to.

    The problem with St. Behe's argument, is that it is insufficient to show merely that an organ cannot be formed from simpler parts in the current environment. It is necessary to show the impossibility (or extremely improbability) that any evolutionary history for the organ could exist (even in an organism very different from the one descended from it). (This issue is discussed extensively in Darwin's Origin of Species.) So what looks like an irreducibly complex organ in a particular organism might in fact be the result of a sequence of adaptations which includes removing parts as well as adding parts.

    To give a toy example that is surely far simpler than anything actually appearing in Nature, suppose that a complex organ with three parts ABC exists such that if you remove any one of the parts A, B, or C you get a useless organism. (I.e. A, B, C, AB, BC, or AC would all be useless or even detrimental when considered by themselves.) Then it may appear at first sight like this is an example of irreducible complexity in the sense that 3 unlikely parts would have to evolve at nearly the same time to do any good. But that doesn't mean you couldn't have an incremental history by some more complicated path involving reductions as well as additions, for example:

    D -> DE -> ADE -> ADBE -> ABE -> ABCE -> ABE

    where at each step only a single letter was added or removed, and at no step did any subset of ABC appear by themselves.

    Behe's argument is like saying that it's impossible to build an arch incrementally, because if you remove any single stone, the whole thing collapses. Of course, an arch is the result of intelligent design, but the intelligent method for building an arch usually involves first putting in a frame and then building around it, and then removing the frame. Not poofing the whole thing into existence at once.

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