Are atheists right to say that you can’t prove a universal negative like “God does not exist”?

I hear a lot of atheists complaining that they shouldn’t have any burden of proof because it is impossible to prove a universal negative, i.e. – “there is no God”.

Here’s a post from William Lane Craig about it.


The first claim is, ironically, usually found on the lips of atheists, who thereby seek to excuse themselves from bearing any share of the burden of proof in the discussion. Usually, the claim is that a universal negative cannot be proved, and therefore the claim that “There is no God” is unprovable. The second claim is typically given as the reason why a universal negative cannot be proved: no matter how much knowledge you have acquired, there will always be more facts that you do not yet know, and perhaps the exception is among them. So one can never prove that there is no God. Perversely, this is somehow interpreted, not as an admission that atheism is indefensible, but as a demonstration that it is in no need of defense!

Unfortunately, the argument is misconceived on a couple of counts.

First, negative, universally quantified statements can be proved. We do this all the time. When we make statements about “all” or “none,” we are speaking about what is the case with respect to a certain domain. We are saying that all or none of the members of that domain have or has a certain property. If the domain is not too large, I can confidently make universally quantified affirmative and negative statements. For example, I am quite confident that “No U.S. Senator is a Muslim.” Or again, if I have a typical sample of the domain, I can make inductive inferences on the basis of the evidence from the sample to the whole, even if the whole domain is too large for me to canvass; for example, taking as my domain all the microbes on Earth, I can confidently assert, “No microbes have brains.”

Now someone might say that while it is admittedly true that negative, universal statements can sometimes be proven, still the point remains that in the case of God, the domain is too large and our sample too small to come to any negative conclusion. But those who propound this argument seem to think that the way one determines whether God exists is by taking a sort of universal survey to see if anything answering to the description of God exists somewhere out there. There are, however, other ways of coming to a knowledge of negative, universally quantified statements than doing an inductive survey.

For example, we can have knowledge of negative, universally quantified statements on the basis of things’ essential properties; for example, “No water molecules are composed of CO2.” (Even if something looked and behaved just like water but was made of CO2 , it still would not be water but just a look-alike substance.) Or if we could show that a notion is logically impossible, we would know that it does not exist; for example, “There are no married bachelors.” Significantly, many atheists have tried just this route to proving that God does not exist, arguing that the idea of a being which is all-powerful or all-knowing is logically incoherent.

[…]Second, the statement that “God does not exist” is not a universally quantified statement. When the theist asserts that “God exists,” the word “God” is being used as a proper name, not as a common noun. It is not a statement like “Dogs exist” but rather like “Lassie exists.” In order to prove that God does not exist, one need not prove that there are no gods whatsoever. Our interest is in one specific being, not in all the other beings which may have been imagined or worshipped throughout the world. So the claim that “God does not exist” is really a singular claim, like “Sherlock Holmes does not exist” or “Harry Potter does not exist.” No one thinks that negative, singular claims cannot be proven.

So there are two ways to disprove a universal negative. Look where you expect the thing to be evident, and show that the evidence is not there. For example, show evidence that the universe is eternal. You can’t have a Creator if you can show evidence that the universe is eternal. The second way is to show that the concept of God is logically contradictory, e.g. – that the concept of a “timeless person” is self-contradictory. Scholarly atheists try to do this, but this has not filtered down to the rank and file, which is why they still hold to these atheist slogans like “you can’t prove a universal negative”. Of course you can.

And finally, Craig concludes with some good advice:

The bottom line is that we have no choice but to go on the basis of the knowledge and evidence that we do have—just we do in all other affairs of life.

Rank and file atheists seem to be very keen on holding out for today’s scientific and historical data to be overturned by Star Trek theories of the future. But the more we study the good, scientific arguments for God’s existence, the harder it is for naturalism to account for it. I am talking about the origin of the universe, the cosmic fine-tuning, the habitability argument, the origin of life, the origin of phyla, scientific evidence for consciousness and free will (e.g. – mental effort) and so on. Not to mention other arguments like the moral argument and the minimal facts case for the resurrection of Jesus.

We have to decide on the data we have now. And the data we have now fits better with a theistic worldview than an atheistic worldview. I can imagine all kinds of data that would argue against Christian theism. Finding the bones of Jesus. The universe being eternal. Experimental evidence for the multiverse. A probable naturalistic scenario for the origin of life. Etc. Arguing against Christian theism is not hard, it just takes work. That’s why intelligent and informed atheists like Peter Millican and Austin Dacey can do it, but rank and file atheists want to talk about “I lack a belief in God” and “I can’t prove a universal negative”.

No one is asking atheists to prove anything, just as theists don’t prove anything. We are asking them to give logical arguments with premises that are supported by the evidence. And that’s what we expect theists to do, too. Once we have all the arguments and evidence on both sides, then people can decide for themselves. You don’t have to “prove” anything in a debate, you just have to state your case as persuasively as possible and the other side does the same, then people decide. Simple.

UPDATE: My favorite atheist Jeff Lowder mentioned this post from Internet Infidels which is on the same topic. His perspective is always worth reading.

UPDATE: And my friend John Fraser has some thoughts on evidence for and against God.

UPDATE: My FB friend Bruce sent me this video:

It’s William Lane Craig answering the question in a debate situation.

21 thoughts on “Are atheists right to say that you can’t prove a universal negative like “God does not exist”?”

  1. “Of course, William Lane Craig.”

    My favorite atheist objection I’ve gotten to date. Like I just said Josef Mengele did some stellar medical work.

    I’m not aware of any apologist who demands the atheist prove his stand is true in the sense of a mathematical or philosophical proof. I’m not aware of any proof in that sense that God exists.

    The standard is what it’s always been: is it more reasonable to believe A or not-A?

  2. I love this post! The only thing I might disagree with is that I don’t think evidence (experimental or otherwise) for a multiverse would do any real damage to the Christian worldview. Ever read anything by Max Andrews or Jeff Zweerink on the multiverse?

    I’m certainly not an expert on the subject, and I don’t even know whether there is a multiverse or not. But surely all a multiverse might show in regard to Christian theism is that the universe God created is so much more diverse and wonderful than we’ve imagined previously?

  3. Can I just write, “Wow?!” I’m still processing all of what was written in this post. I’m just glad that we have brothers and sisters, who are trying to think these things through and present the arguments with clarity and, I hope, with love. I might use some of this in my Sunday School class tomorrow.

  4. Whether there are some puzzling features of the universe is irrelevant (it must be noted that naturalistic explanations have done pretty well so far). Christians really only care about the christian god. The evidence for his non existence is overwhelming. Just read the bible. It’s a completely untenable position for an educated individual. Christopher Hitchens stated it well. He was uninterested in the christians desperately clinging to ‘fine tuning’ or’ first cause’ or ‘prime mover’. As if that gave some support to the monstrous deity of the old testament. As he said “you’ve got all your work still ahead of you”.
    The longer version:
    “I can’t answer that. I can’t disprove it. It could be true. All you would’ve done was establish the possibility that deism was a reasonable position to hold. Which, I would say that until Darwin and Einstein it probably was. It was the sort of thing that an intelligent person might have to end up believing because the orders and rhythms of the nature and the cosmos don’t seem very likely to be accidental. But if you’ve established deism you’ve got all your work still ahead of you to be a theist. You have to show that this god, this person who went to all this trouble with physics, cares who you sleep with or how or whether you should eat a pig or not or what day you should observe as holy. Now, I don’t see how you get from your uncaused cause to that, to the idea that we are divinely created, supervised by someone who cares for us. That’s something for which there can never be made any evidence. “

    1. ”You have to show that this god, this person who went to all this trouble with physics, cares who you sleep with or how or whether you should eat a pig or not or what day you should observe as holy.”

      That will have to come from the evidence of History and the interaction of that God with history. Of course the fine-tuning argument does not prove the identity of God per se. Only that intelligence and agency had a hand in creation.

      Now if that God entered history and interacted with man. Then we may know who he is and how he is like.

      If the scriptures in terms of historical accuracy and fulfillment of prophecy is to be proved.

      1. So?

        If gravity was stronger or weaker by one part in 1040 (10,000 trillion trillion trillion) stable, long-living, life-sustaining stars like our sun could never exist. The same applies to the ratio of the mass of the proton to the mass of the electron, as well as the strong nuclear attraction Those numbers are evidently variable, yet their settings mean absolutely nothing unless you have another universe against which you can compare and contrast ours.

        Do you have another universe against which we can compare ours?

        1. “Those numbers are evidently variable, yet their settings mean absolutely nothing unless you have another universe against which you can compare and contrast ours. ”

          I see no justification for requiring another universe for comparison although it’s convenient for the skeptic to insist on evidence which can’t possibly be produced! But we can construct mathematical models of hypothetical universes which is exactly why we know what would happen if these variables were different. There is no need for empirical confirmation of that, and such confirmation is impossible to attain anyhow.

          1. Hi John, hope you’re doing well

            Where does “convenience” come into it? One cannot make a value judgment for or against something unless one has something to compare that thing against. That’s just common sense. Alter the initial conditions of the Big Bang by as little as one part in 10 trillion trillion trillion trillion trillion and our universe would be unrecognisable. How on earth can you then claim that life could not spring up in that new universe? It might not be life as we presently recognise it, it probably wouldn’t be, but there is no way you can make a claim that life could not (would not) emerge under these different conditions. Perhaps those conditions would be far better suited for the creation of life-bearing planets, and that new universe is literally blooming with life. Perhaps you don’t know this, but our universe, for example, is far better tuned for the production of black holes, not life-bearing planets. Knowing that, are you going to alter you claim then to say this universe was created to produce black holes, and life is just a residue cast off from its real purpose; the thing it was clearly designed for?

            I can summarise your thinking as such: Consider a puddle of water sitting in a hole. That hole is remarkably well-suited for the puddle, isn’t it? It fits so well, in fact, that it’s almost like the hole was made just for the puddle! The hole must have been made for the puddle!!

          2. Read this, and don’t comment again until you understand the science:

            The author explains his peer-reviewed paper here:

            I’ve published a review of the scientific literature, 200+ papers, and I can only think of a handful that oppose this conclusion, and piles and piles that support it. Here are some quotes from non-theist scientists. For example, Andrei Linde says: “The existence of an amazingly strong correlation between our own properties and the values of many parameters of our world, such as the masses and charges of electron and proton, the value of the gravitational constant, the amplitude of spontaneous symmetry breaking in the electroweak theory, the value of the vacuum energy, and the dimensionality of our world, is an experimental fact requiring an explanation.” [emphasis added.]

            “By several theoretical physicists (from Krauss to Stenger)”. I’ve replied to Stenger. I had a chance to talk to Krauss briefly about fine-tuning but I’m still not sure what he thinks. His published work on anthropic matters doesn’t address the more general fine-tuning claim. Also, by saying “from” and “to”, Carrier is trying to give the impression that a great multitude stands with his claim. I’m not even sure if Krauss is with him. I’ve read loads on this subject and only Stenger defends Carrier’s point, and in a popular (ish) level book. On the other hand, Craig can cite Barrow, Carr, Carter, Davies, Deutsch, Ellis, Greene, Guth, Harrison, Hawking, Linde, Page, Penrose, Polkinghorne, Rees, Sandage, Smolin, Susskind, Tegmark, Tipler, Vilenkin, Weinberg, Wheeler, and Wilczek. (See here). With regards to the claim that “the fundamental constants and quantities of nature must fall into an incomprehensibly narrow life-permitting range”, the weight of the peer-reviewed scientific literature is overwhelmingly with Craig. (If you disagree, start citing papers).

          3. John Zande,

            I don’t think you understand the argument. If these variables were slightly different, you wouldn’t have planets at all, so you wouldn’t have better conditions for life-bearing planets. Just the existence of planets and heavy elements requires an incredibly narrow range of fine-tuning, and this is to say nothing of the remarkable initial low entropy condition. So when you say our universe is “far better tuned for the production of black holes, not life-bearing planets,” you seem to think that the relative number of black holes versus life-bearing planets has something to do with the argument. When we talk about fine-tuning we’re talking about what is necessary to have even ONE planet capable of sustaining intelligent life forms like homo sapiens, and to have elements with the properties that we observe. As I said above, we don’t need another universe to compare it to, we know from the mathematical models what would happen. But tell me even one cosmologist who has a model for producing a universe “literally blooming with life” (I assume you mean with many more life-bearing planets than we observe presently). Most cosmologists that I have seen who talk about this talk about how remarkable it is to have a universe that can support intelligent life AT ALL, including the famous quote from Fred Hoyle: “A common sense interpretation of the facts suggests that a superintellect has monkeyed with physics, as well as with chemistry and biology, and that there are no blind forces worth speaking about in nature. The numbers one calculates from the facts seem to me so overwhelming as to put this conclusion almost beyond question.”

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s