In conversations and debates between atheists and theists, is it enough for the atheist to assert that they are skeptical of theism without providing justification, or does the atheist bear the burden of proof to show why/how the reasons for belief given by the theist are uncompelling/unconvincing?

If the atheist does bear this burden of proof, would it make sense to be skeptical of the atheist's skepticism until they meet their burden of proof? Moreover, would the atheist need to show that the reasons provided by the theist are objectively unconvincing (no human being, including theists themselves, should find these reasons convincing), or is it enough for the atheist to explain how they personally/subjectively find them unconvincing, while remaining open to the possibility that these reasons might be legitimately convincing for other people?

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    The burden of proof for mere doubt is much lower than for definitive claims. A skeptic or agnostic does owe some justification for their skepticism, but far short of "proving" that the other side's arguments are "unconvincing" (whatever that means). However, atheists are not agnostics, they have definitive claims of their own and the burden of proof with them. In practice, these debates have been going on for so long that arguments of both sides and objections to them are easily accessible, so merely alluding to them is often enough.
    – Conifold
    Commented Nov 11, 2023 at 11:46
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    As per basic logic: If someone is trying to justify their own atheism, it's enough for them to explain why a given theist justification is unconvincing for them personally. If someone is trying to argue that atheism is the rational position for everyone, then they'd need to explain why a theist justification should be unconvincing for anyone.
    – NotThatGuy
    Commented Nov 11, 2023 at 21:09
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    The answer to this is going to depend heavily on definitions. If atheism is defined as the lack of theistic beliefs, then you get one answer. If it is instead defined as the positive assertion that there is no deity (sometimes called antitheism) then you get an entirely different answer. Commented Nov 12, 2023 at 2:16
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    Are you sure you don't mean agnostic? The true atheist is the one who says "There is no God" while the agnostic is the one who expresses doubts of any god at all.
    – Joshua
    Commented Nov 13, 2023 at 4:21
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    If you want to have a conversation on the subject, you will need to justify why the other person's position is not "good enough". Of course, not all conversations are worth having. Idk if this is really a ”philosophical" position though. Commented Nov 13, 2023 at 12:45

19 Answers 19


I think gnasher729 and NotThatGusy make a great first point - "God" is too fuzzy a concept. Any discussion of God first needs to establish what properties we are assuming God has.

However, for any specific conception of God, there are negative atheists (incorrectly called agnostics) and positive atheists (which is what a lot of people think of as atheists):

Negative Atheism: I lack a belief in god. This is a position that arguably we all hold as newborns, our pets hold (unintentional/unconsidered negative atheism) and a great many avowed atheists and so-called agnostics hold (intentional/considered negative atheism). A negative atheist (of the considered variety) has an obligation to engage with extant theistic arguments to show they are not valid or sound. However, they are not required to produce arguments for the non-existence of God.

Positive Atheism: This position has its work cut out for it, in much the same way as the Theist does. There is a burden to produce and defend an argument as to why a God doesn't exist, not just that current arguments for God's existence fail.

Michael Martin's (somewhat dated now) Atheism: A Philosophical Justification uses the positive/negative framework as well, and that is where I am taking it from.

That addresses the logical part of your question. With regards to if we admit an argument can be convincing to others, but not us, that depends very much on what epistemology we bring to the premises in the arguments. Evidentialists will conflict with non-evidence-based explanations such as cosmological arguments etc.

Clearly, arguments for certain versions of God are very convincing to some, and the entire field of Christian Apologetics has produced some very creative and clever arguments - of the ones I've read, some do succeed in the narrow sense of generating skepticism of naturalistic epistemology and ethics. However, while they do make space for God, they have a hard time going from that to the truth of, say, the Nicene Creed. That would be a lot of ground to cover!


I'd say the burden of proof is on the theist. The theist asserts the existence of some god. The burden of proof lies with the one making the claim.


The answer is not going to be "the theist has the burden of proof" nor "the atheist has the burden of proof".

Before you can answer "Who has the burden of proof?", you need to ask: "What is the purpose of the discussion?".

Theists believe in a god, atheists don't believe in a god, and none of of them starts with any burden of proof. Why would they? Their belief is personal. However, if they engage in a discussion about the existence of god, then presumably they're trying to achieve something with this discussion.

Perhaps one of them is trying to convince the other; in this case, the one who is trying to convince gets a burden of proof.

Perhaps one of them is trying to extend their horizon by trying to understand the other's viewpoint; in this case, the former gets a burden of open-mindedness and the latter gets a burden of proof as a matter of courtesy.

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    Lucky 10000: The theist is usually interested in theocracy, and is directed by their clergy and holy texts to enact it by any means whatsoever. In this case, the debating theist is practicing apologetics. Such debates aren't merely about personal beliefs, but about societal policies.
    – Corbin
    Commented Nov 13, 2023 at 17:11
  • Especially when they use pointy loud sticks to convince you to agree with them.
    – Scott Rowe
    Commented Nov 13, 2023 at 17:30
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    I'd say that 'not believing in god' is not a belief in itself, at least for agnostic atheists (most atheists). It's an absence of belief. Calling atheism a belief is like calling 'not playing sports' a sport.
    – Dennisch
    Commented Nov 14, 2023 at 17:29
  • @Dennisch That's just a matter of definition. I'm used to "agnostic" meaning "not having a belief that God exists" and "atheist" meaning "having a belief that God doesn't exist". Apparently you are used to different definitions. I don't think it matters much to the point I was trying to make. (Most atheists and agnostics I know don't care either way and wouldn't label themselves anything anyway.)
    – Stef
    Commented Nov 20, 2023 at 21:11
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    When I here some describe atheism as a belief, I remind them that there are more states than "belief" and "disbelief". There is "conclude". We need not "believe" the Earth is a globe. We started with theory/suspicion, we thought, and calculated and tested. Then concluded. And then many times over, we confirmed our conclusion. Some atheists might be "disbelievers". I am an atheist that concludes there are no supernatural entities. Not "I believe there are not"... I "conclude there are not". Commented Feb 8 at 7:52

Unless one is a fideist, one is essentially bound to onus probandi. From WP:

[T]he burden of proof lies with the one who speaks, not the one who negates... is the obligation on a party in a dispute to provide sufficient warrant for its position.

In the case of supernatural and extra-natural beings, then we observe Carl Sagan's aphorism: Extraordinary claims require extraordinary evidence.

Any reading of the history of religion will expose how much the concept 'God' is abused for political ends.

  • Well, it is perhaps not clear what is the statement here, and what the negation. "Somebody made all this" was the obvious and intuitive worldview since the first spark of consciousness emerged a million years ago or so. "It all emerged by a series of complicated and often unknown processes, and nobody knows why it is here or how it actually started" is an unintuitive, new claim. The reaction to smile, shake one's head and ask the speaker to explain that stark claim seems not unreasonable. Commented Nov 12, 2023 at 10:55
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    @Peter-ReinstateMonica "Somebody made all this" was the obvious and intuitive worldview since the first spark of consciousness emerged a million years ago or so - I'd actually be quite interested in reading about this prehistoric view - do you have a good source?
    – yoniLavi
    Commented Nov 14, 2023 at 0:49

Practically in informal circumstances the burden of prove lies with whoever needs to convert the doubter. If you are an atheist trying to persuade a Catholic their belief is misguided, the burden of proof lies with you. If you are a Catholic trying to convert an atheist, the burden of proof lies with you.

In other circumstances, the burden of proof is allocated by convention. In UK criminal law, for example, there is a burden of proof on the prosecution to prove guilt beyond reasonable doubt. In the regulation of medical devices, the burden of proof lies with the manufacturer to show the device is safe and effective. And so on.

  • Downvoted for confusing the burden of disproof with the burden of proof. See Russell's teapot for a good example of why they are not equivalent.
    – Corbin
    Commented Nov 13, 2023 at 17:12
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    @Corbin thanks, but the conflation is deliberate- I'm well aware of Bertie's teapot. I began my first sentence with the word "practically', because if you are faced with a group of fanatics who insist upon the existence of the teapot, and you feel you need to disabuse them, the burden of proof most certainly lies with you. Commented Nov 13, 2023 at 17:42
  • You're still conflating the process of discovering contradictions with discovering proofs. A proof is a sequence of syntactic rewrites from axioms to theorems; a contradiction is a syntactic object which maps other objects to impossibilities (e.g. inhabitants of an empty type.) In classical logic, they are similar; but not in intuitionistic logic in general. Since it is possible for two people to debate without either being correct, debates don't have LEM, and so classical logic is not appropriate.
    – Corbin
    Commented Nov 13, 2023 at 18:09
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    Cheers, but you are conflating philosophic principles with the nature of my answer which was about practicalities. Your definition of proof in your comment above refers to a particular use of the word which I certainly never intended, so you are arguing with me at cross purposes. All the best! Commented Nov 13, 2023 at 18:20

Supernatural claims always carry a severe burden of proof. Since the typical theistic claim involves supernatural causes or effects, it also carries a burden of proof.

In general, skeptics carry no burden of proof whatsoever.

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    @IoannisPaizis I imagine the evidence for something physically impossible happening would be similar to the evidence for something physically possible happening. The difference being that the former would have no natural explanation. Commented Nov 12, 2023 at 1:07
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    @IoannisPaizis By providing proof that does not require any type of faith or belief. Any ‘proof’ that doesn’t meet that criteria results in reasoning that assumes the conclusion because the ‘proof’ is only a valid premise if the conclusion is true. Commented Nov 12, 2023 at 3:40
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    @IoannisPaizis: I'll grant that e.g. miracles could be empirically documented and have no natural explanation, in theory; the famous skeptic Randi carried out several investigations of miraculous claims, for example. Different skeptics will require different proofs, of course.
    – Corbin
    Commented Nov 12, 2023 at 4:06
  • @user132647: The Big Bang is a theist concept introduced to make sense of the early universe. The skeptical scientist will only say that we have theories which, when extrapolated, imply that the universe was once very small and hot; and will readily concede that those theories do not admit singularities.
    – Corbin
    Commented Nov 13, 2023 at 17:15

I strongly disagree with the accepted answer. Proving the non-existence of something is in most cases impossible. In science, most of the time we need to prove the existence.

That's what the Russel's Teapot analogy tries to teach us. Someone makes the claim that there's a pink magical teapot orbiting around the sun. It's too small to be seen by telescopes, but... it does exist!

Now... would you say it's fair to shift the burden of proof onto you, to disprove its existence? Of course not! If someone makes a claim of existence, then it's up to them to provide the proof of existence before anyone else is supposed to prove the opposite.

Atheists do exactly this. Regardless of the distinction Annika makes, all atheists pretty much say the same thing: "There very well may be a god, but so far no proof has been provided. Thus, there is no reason to believe there is one."

  • I think that the "Reindeer can fly" argument is slightly better - all one can ever do is that show that THAT reindeer didn't fly on THAT occasion. After pushing fifteen gazillion reindeer off a cliff, I still can't prove that they can't fly. (With the teapot I could in theory send a probe to have a look.)
    – MikeB
    Commented Nov 14, 2023 at 15:53
  • What part do you strongly disagree with? The definition of positive atheism? You state: “ Regardless of the distinction Annika makes, all atheists pretty much say the same thing: "There very well may be a god, but so far no proof has been provided. Thus, there is no reason to believe there is one." You’re making an empirical statement that practically all atheists are negative atheists but. That is not the point of the question. I was showing when an atheist would reasonably be expected to bear the burden of proof.
    – Annika
    Commented Nov 21, 2023 at 23:46
  • @Annika that's exactly the part I disagree with. The distinction between positive and negative atheism isn't something atheists make. It sounds like something a religious person would invent. All atheists would believe in God when provided with the evidence. However, there's no such evidence to be found anywhere. So God doesn't exist. That's the only conclusion an atheist can draw. In that regard, atheists and agnostics aren't all too different from each other. As a result of that: I can only strongly disagree with you that "positive atheists have the burden of proof on them".
    – Opifex
    Commented Nov 22, 2023 at 8:50
  • @Opifex positive atheism is not a term invented by theists. It was introduced a while ago by several atheist philosophers: en.m.wikipedia.org/wiki/Implicit_and_explicit_atheism
    – Annika
    Commented Nov 22, 2023 at 13:03
  • @Opifex additionally, while I agree that most atheists are of the negative/weak type, from the point of view of when an atheist would have burden of proof it is the distinction I made that matters - “God does not exist” is not equivalent to “I do not accept the existing arguments for God.”
    – Annika
    Commented Nov 22, 2023 at 13:15

The basic rule of a philosophical discussion is to support one's thesis by some arguments.

History of philosophy shows that neither the theist nor the atheist have succeeded in convincing the opponent by their arguments. The question of the existence of God remains undecided.

A new start: To consider the basic statements of both parties as two hypotheses and discuss the explanatory value of each hypothesis. Such a change of the focus may open up a new line of discussion.

Added: I refer to discussions in European philosophy and theology about the Abrahamic god.


For me this is very simply answered: the question is invalid. To ask it at all is based on fallacious understanding of the issues involved.

I prefer the famous definition of "atheism" often stated as something like "an atheist is someone who believes the evidence of the existence of God is roughly on the same level as the evidence for the existence of werewolves."

The scientific method says you don't prove anything; instead, you disprove the contrary hypothesis (called the "null hypothesis"), by showing that this opposite hypothese is impossible.

For instance, let's say I hypothesize "I think Jim exists." Can we test this theory? Well, to test this scientifically, we'd take the null hypothesis, "Jim does not exist." Can we prove this is impossible? Well, you might call Jim over to tickle me. In this case, I would say, we have significant evidence that the null hypothesis absolutely cannot be true, because, we all just directly observed Jim's presence and disarming affectionate assault; and, what's more, I'm doubled on the floor laughing. So, "Jim exists" is a good theory, and we have met our burden of proof (even though, obviously, there's still room to argue alternative theories. In science, the most likely answer is the best one to go with; until something contradicts it by fitting better with the previously established-and-tested evidence. All you can ever do is prove what correlates best with present understanding, not what's "true". Nothing is ever "true" in science, it's simply "our best available model.")

More realistically, the hypothesis "This new treatment is effective in curing moderate to severe Crohn's disease" is considered valid if we disprove the null hypothesis "This new vaccine is not effective in treating moderate to severe Crohn's disease" by showing a statistical correlation between treatment use and subsequent moderate to severe Crohn's disease remission that is too far outside the bounds of random probability to be dismissed as a chance occurrence. Again, this doesn't provide 100% proof, but, we go with strong enough likelihoods (and in this example, as in many, in the lab there is a rigorous mathematical definition of "strong enough", it's not just a researcher kind of eyeballing it and deciding "looks good enough for me!". Google "confidence intervals" if interested in that tangent.)

However, some statements are not falsifiable... that's to say, it's not possible to come up with a null hypothesis that it is possible to disprove. I might say, "I believe someday a boy will be born who can swim faster than a shark". The null hypothesis "A boy will never be born who can swim faster than a shark" cannot be disproven, because to disprove it, you would have to wait around literally forever to know for sure about every boy ever to be born and check their lap time in the pool. On a practical level it's just not possible to disprove.

So, "I believe someday a boy will be born who can swim faster than a shark" is said to be "non-falsifiable"... it is not a valid question to even discuss "burden of proof" on, at least, not in the scientific sense. It is not a question we can scrutinize empirically, only conjecturally.

A big part of this is measurability by our human sense. For a hypothesis to be falsifiable, the full attributes of null hypothesis must fit within our perceptions, because "disproving" requires disproving every possible case. You must, on a practical level, have a ruler big enough to measure it, and it must be something small enough to measurable within the time constraints of human effort.

So to speak of a "burden of proof" with regards to the infinite, immortal, invisible or immaterial doesn't even really make sense.

Now, I once had a Christian friend give me a really interesting answer to these sorts of questions, in different but related terms. I was needling him about logical inconsistencies in his faith, or some such, and he cut me off, and told me something I've carried with me to this day. He said (something along the lines of) "You're trying to reason me out of my belief. But it's not reason, it's faith. I made a leap of faith. I put my faith in these things being true. So you're not going to reason me out of it, because I didn't use reason or proof to get there. I just have faith in it. "

I had a lot of respect for that answer.

One thing you have to remember, I'm fond of saying, is that reason and faith aren't opposites—they're orthogonal. They're two perpendicular dimensions, having nothing to do with each other. What someone might say is true because it's the best current model that can be arrived empirically at empirically, and what someone has chosen to have faith is true, are two totally unrelated things. We only confuse them with each other because they both get called by the same word: "belief". (It's kind of like how the work of Ravel, Bill Evans, the Angry Samoans and that boring Donavon Frankenreiter song from 20 years ago all get called "music". It's like, yeah, but, really, no.)

So, having started by showing how I think a person of a scientific bent would reject the notion of a "burden of proof" for or against a deity as not even a valid question. We now see that to a person of deep religious faith, the notion of a "burden of proof" is also invalid. Proof has nothing to do with faith.

And to me, as an apizzaist, er, atheist (sorry, I get confused whenever I don't see any evidence of the existence of a deity while I'm also not eating a pizza), there's nothing to prove. The fact that I don't feel I've seen any evidence of the existence of deities isn't falsifiable either. And it's not a belief. Show me the evidence, and I'll change my mind.

I always say, I'm the easiest guy in the world to convince of anything. All you have to do is show me the evidence.

BTW, I used to call myself an agnostic, but a friend made fun of me for it. "Oh, are you going to say now the jury is out on fairies and werewolves? Are you going to say you think they might exist too, just because you can't conclusively prove that they don't?" I had to admin, no, I don't think there's even a chance that any of those things might exist, I'm not agnostic on fairies or werewolves or Odin or Zeus or Pikkiwoki or God or Quetzalcoatl.

But, to refer to a burden on me to prove any of it to someone else, or on anyone else to convince me of anything, is, to me, just a misunderstanding of what both scientific reason and religious faith really are. To try to debate it at all is misguided. It's literally not debatable, from either a scientific nor a religious standpoint.

And on a personal level too, it just doesn't seem like a useful topic to discuss, or even one there's any reason to, whether between two people who agree or disagree, except maybe as a bit of an intellectual exercise in omphaloskepsis. I'm as fine if people want to put their personal faith in things there is no evidence of as they should be (er, as I wish they'd all be) with me not wanting to. I don't see how needing to change anybody else's mind factors into it at all. That's not religion, that's politics. Not that the two have much of a history of keeping their fingers out of each others' drawers. But that's another issue.

  • What someone might say is true because it's the best current model that can be arrived empirically at empirically, and what someone has chosen to have faith is true, are two totally unrelated things. We only confuse them with each other because they both get called by the same word: "belief".... I prefer to consider other terms, and I try not to have beliefs. Conclusion (when warranted), reserve judgement pending further information, expect it is true, extremely probable... or I resort to percentages... 80%, 90%, 95, 98, 99, 99.9% etc. "Belief" I sincerely do my best to abstain from. Commented Mar 8 at 7:05

There is no such thing as a burden of proof. Hence, the question is unfounded. And if there is, it would be like any other ought thought of in history.

The same way that there is no way to objectively prove that one should eat strawberries instead of blueberries on a Friday is the same way you can’t show who and in what cases the burden of proof relies on.

No one “ought” to do anything or justify anything.

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    I'm not going to downvote, but the nature that there is no such thing as a burden of proof is tantamount to saying there is no such thing as logic, no such thing as evidence, no such thing as reason. I think that's a hard sell, especially on a philosophical website. ; )
    – J D
    Commented Nov 12, 2023 at 14:19
  • A burden by definition is an ought. Evidence, logic, and reasons, are not oughts. So the hard sell would be to show that an ought follows from the notion of logic and reason. But a great philosopher whose name I’m sure you’ve heard of already showed that you can’t get an ought from an is.
    – user62907
    Commented Nov 12, 2023 at 15:28
  • Every Is is indirectly an Ought, and every Ought indirectly is an Is, especially in one's choice of logic. Hume was a great thinker, but you are finding refuge behind men with outdated thoughts. Philosophy has grown a tad since Hume, and in the case of the approximate distinction of Is and Ought, comes theory-laddenness. There is no absolute Is, not even in science.
    – J D
    Commented Nov 12, 2023 at 16:01
  • @JD You cannot be a realist without thinking that there is an absolute is. The debate between realism vs. anti realism is a whole different subject.
    – user62907
    Commented Nov 12, 2023 at 16:16
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    Anyway, keep up the contributions! I enjoy yours.
    – J D
    Commented Nov 12, 2023 at 16:28

Replace "atheist" with "A" and "theist" with "B." Run through the question and see if it makes sense to give the burden of proof to "A" or "B." If it is difficult to do so, then that suggests that one has a-priori beliefs about the positions of "atheist" and "theist."

We often talk about "the burden of proof" as though there is some referee for all logical arguments which is going to issue a yellow card for anyone not following the rules. There is not. "The burden of proof" is a simplified tool to approach justifying how one acts after the debate without having to go into tremendous detail.

Sometimes there is such a referee. In legal systems, a referee (the government) has structured the debate with an explicit design such that "burden of proof" is a very clear concept that can be applied. But this is not always the case.

Consider an atheist walking into a Church and making claims. Consider said atheist making the same claims at a Flying Spaghetti Monster (FSM) convention. Consider a theist walking into a Church and making claims. Consider said theist making the same claims at a FSM convention. If you feel the burden of proof shifts in those extreme environments, that suggests you find that the burden of proof can be quite situation dependent.

Personally, I like the rule of G. K. Chesterton's fence. It puts the burden of proof on the one doing the action. It also fits well with the nature of modal logic, which sidesteps a lot of closed world behaviors that inspire the need for burden of proof (positive and negative assertions have the same behaviors):

There exists in such a case a certain institution or law; let us say, for the sake of simplicity, a fence or gate erected across a road. The more modern type of reformer goes gaily up to it and says, "I don’t see the use of this; let us clear it away." To which the more intelligent type of reformer will do well to answer: "If you don’t see the use of it, I certainly won’t let you clear it away. Go away and think. Then, when you can come back and tell me that you do see the use of it, I may allow you to destroy it."

But I will not claim that is the de-facto rule for burden of proof. Its merely a heuristic that I have found works well enough in varied circumstances to put it forth for consideration. And I find it works well enough that one can use it to critique the concept of any particular line in the sand described as "burden of proof." It is, in my opinion, good sound advice, but one can certainly argue about circumstances where it is not the ideal line to draw, so it isn't sacrosanct.

  • Given a formal system, the burden of proof is the expectation that provable claims about the formal system should be equipped with explicit syntactic proofs. This is directly connected to the fact that formalizations of various paradoxes, e.g. the paradox of the stone, have never been refuted by theists.
    – Corbin
    Commented Nov 13, 2023 at 17:20
  • I guess religious people should stop and consider deeply before trying to change the minds of non-religious people.
    – Scott Rowe
    Commented Nov 13, 2023 at 17:26
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    @Corbin There was a time where I felt formal logic paradoxes were an effective argument against various positions. What I have found is that pretending humans think formally is less than reliable.
    – Cort Ammon
    Commented Nov 14, 2023 at 3:01
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    @ScottRowe And the same goes for the non-religious minds trying to change religious minds. At least that would be the interpretation I draw from Chesterton's Fence. You are, of course, free to draw otherwise.
    – Cort Ammon
    Commented Nov 14, 2023 at 3:02
  • @Corbin: The paradox of the stone is answered in the Bible. "God is not a man that he should change his mind."
    – Joshua
    Commented Nov 14, 2023 at 3:48

If the properties and definition of god include observable effects in the empirical universe, then the burden of proof should be on the person advancing the explanation that opposes the science and its principles the most. I.e. the least parsimonious explanation, the one that is most likely wrong, given all we know about how the universe works. The one that rejects the null hypothesis or requires the most changes and additions to science. The one that is the most inconsistent with empirical observation and well-established scientific facts, theories and laws. Or the one that has the most unproven/undemonstrated premises, including hidden ones.

Note that this doesn't necessarily exclude any unknown, complex, hidden causes, as many such things have been discovered in nature. But before the "empirical breadcrumb" was found, there was no justification for claiming they existed, and the probability was almost as low as any other false explanation. The point of science is to find the most accurate, reliable answer as soon as possible by filtering out an infinity of inaccurate answers, and do so in a way that doesn't exclude the more accurate ones at any time in the search process. I don't think many people, on both sides, realize this.

At least in principle, one can compute the probability of a god with properties {P1, P2, ... }, existing and causing events {E1, E2, ... }, relative to all our current knowledge of the universe, and if that number is near 50% (i.e. random coin-flip certainty), then skepticism is proven.

So, no, there is no need (nor is it possible) to show that the reasons provided by the theist are objectively unconvincing. It is enough to show, subjectively (relative to all evidence about how the universe works), that an atheist or an unbiased scientist would find them unconvincing, unreliable or inaccurate, because science is relative to a finite set of data, and Quantum Mechanics has given us over 99.99999999% accuracy in atomic properties, for example, due to the principles given above.

Many people are not convinced by science and its optimal (but obviously not perfect) method of maximizing accuracy and reliability. For example, climate change deniers and flat-earthers, so of course one has to accept that some people are simply unreachable.


Pragmatically, the burden of proof is on who is trying to convince other folks to think differently than they do. It depends only on who is the proselitist.

A (a)theist who is not trying to convince you has no burden of proof.

And if a theist and an atheist are arguing with one another, then each of them bears the burden of proof for whatever she is asserting.


When there's a prevailing belief, the burden of proof falls on those who claim otherwise. For instance, when a geocentric universe was the common belief (it just seemed obvious to most people, and even what counted as "scientists" of the time found ways to explain it), astronomers like Copernicus and Galileo had to make convincing arguments to persuade people. Similarly, Darwin needed to provide a detailed argument for evolution by natural selection -- it was asking people to accept a change to the existing paradigm.

In the US, 84% of people believe in God. They may not have rational reasons for this belief, but that doesn't really matter -- they still consider it to be true. Therefore, it falls to the atheists to try to convince them otherwise.

Argumentum ad populum may be a fallacy, but it's often the best guideline for most people -- they may not have the necessary background to evaluate detailed arguments. And usually there's a rational reason why the majority believe something (although there are certainly other widespread incorrect beliefs).

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    I really hope that 84% figure isn't true, but anyway why should I care? Many people have pointed out that believing in God is theoretically "a good thing" so personally I don't care, just as long as those beliefs don't encroach on my own life/liberties etc. (Which they sometimes do, but that's another story!)
    – MikeB
    Commented Nov 14, 2023 at 15:56
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    I took the question to presume that we have a need for one side to convince the other, and is just asking which side has the greater burden of proof. Of course, you can reject the premise, and then it's moot. But in practice, the beliefs of the majority do often encroach on society in general, so the debate becomes necessary.
    – Barmar
    Commented Nov 14, 2023 at 16:33
  • Awww! Why the atheists? There are 1.2 billion Hindus, a half-billion Buddhists, and a whole bunch of followers of other faiths and belief systems. Can't they do it? Commented Feb 8 at 7:46

The proof of God's existence is similar to proof of paternity. Prior to 1900, before DNA and blood-typing, there was no definitive way to prove paternity other than testimony. Blood-typing (developed in the 1900s) gave the ability to definitively show a person is not the father, but it was DNA that provided a definitive test for paternity.

So before 1900, fathers existed without physical proof.

As of this writing, there is no definitive test for the existence of God. So the proof of the existence of God may require tools that have yet to be discovered. The burden of proof rests with those seeking the truth whether its theist or atheist.


No. The burden of proof lies with the proposer. Onus probandi incumbit ei qui dicit, non ei qui negat. I define atheism as the lack of belief in God. It is not the proposition that God does not exist.

  • I think you misunderstood my question. I'm asking about reasons offered by theists to justify their belief in God. If the atheist rejects these reasons, does he have the burden of proof as to explaining why these reasons ought to be rejected? Say, if William Lane Craig comes by and presents the Kalam Cosmological Argument and the Fine Tuning Argument in defense of his belief in God, would an atheist, in order to contribute to the discussion, have no choice but to say something about those arguments and eventually show how they are unconvincing (in order to remain an atheist)?
    – Mark
    Commented Nov 15, 2023 at 16:27
  • The same principle applies. Whether I propose that God exists or that I believe in God because x, the burden of proof lies with me. Just like, I believe that the moon is made of green cheese. I believe this because I went there and ate some. Onus probandi lies with me. Just as with Russell's Teapot. The alleged equivalence between theism and atheism is fallacious.
    – Meanach
    Commented Nov 15, 2023 at 17:17

Do atheists bear the burden of proof in showing why/how the reasons presented by theists are unconvincing?

Nah. Here is why.

It is not "Christians VS Atheism". Is it? (Rhetorical). There are 8,000,000,000+ humans. There have been a hundred billion more, come and gone in the past, and some of them had gods too.

So. If a "burden of justifying disbelief" were a valid burden to expect "non-believers" to carry... ... Christians would have thousands of gods to have to justify not believing in.

And wouldn't we have to consider "supernatural beings and entities" in general?

Demons. Trolls. Bigfoot. Leprechauns.

My Beloved Nessie, the Monster of Loch Ness. None should dare claim she is unreal to my face, in person, unless they can prove it!

I think NO. Conclusively NO. The burden of justifying disbelief need never fall on the shoulders of disbelievers.

Do you see and agree?

  • Do you see and agree? - No, because I think you misunderstood the question. The burden of proof I'm talking about is not on the claim that those entities do not exist, but rather on the claim that the arguments offered by those who believe in those entities are unconvincing. Those are two different claims. So, taking 'Leprachauns' as an example, the correct analogy would be gathering all the arguments that Leprachauns advocates have offered in favor of their existence, and then claiming that those arguments are unconvincing. It's a claim about the arguments.
    – Mark
    Commented Feb 8 at 10:59
  • 1
    If Leprachauns advocates offer no arguments, there is no burden of proof associated with rejecting their non-existent arguments.
    – Mark
    Commented Feb 8 at 11:03
  • Begorrah, fine then, lets leave the little green Earthlings out of the equation. That enter key not starting a new line gets me every time! Where I was going... there are claimants that offer "arguments" and "evidence" and yet are easily recognized as not necessarily aligned with true reality... examples include bigfoot, and (yep, lol) little green non-Earthlings. Remember Omuamua and that one professor who put a lot of effort into kicking up the mystic "we don't know it aint aliens"?? He was a good example. Commented Feb 8 at 13:03

Because of the fact that the God concept has strong connotations for many people it's easy to get "trapped" into a polarized way of thinking.

Firstly let me start with a pitfall in the concept of theism:

  • Christianity, Islam, Judaism, and Hinduism are theistic religions.
  • Buddhism, Taoism, and in general eastern religions are non-theistic.

Secondly, atheism is commonly understood as:

  • non-acceptance OR
  • rejection of theism.

Thirdly, we have agnosticism which covers a range of beliefs from unknown or unknowable of the concept of God to believing in the existence of God but regard the basis of this as unknown or unknowable.

And somewhere inside this landscape we have all these people that - without identifying themselves as belonging to a specific category - somehow believe in something more profound than that their lives are just a matter of physical and material interactions; they one way or another believe that there is more to life than this.

In order to get out of this mess, we could try to draw a line, by defining it as :

  • the belief that everything arises from natural properties and causes, and supernatural or spiritual explanations are excluded or discounted.

But even then, isn't it difficult to get a side?

Although the spirit is "banned" in our times, there is no way we can get out without it.

The "burder of proof" lies in all of us.

  • Profoundness does not require a deity or something transcendent. I see it all the time.
    – Scott Rowe
    Commented Nov 13, 2023 at 17:28
  • @Scott Rowe, so from where does it come out from? Commented Nov 13, 2023 at 17:33
  • The profoundness appeared at the moment I stopped believing in anything, even my separate existence. There is nothing bigger than "that which is".
    – Scott Rowe
    Commented Nov 13, 2023 at 17:43
  • 1
    @Scott Rowe, well done. That's the way of approaching the spirit. I am surprised that you found the way intuitively. Commented Nov 13, 2023 at 18:10

On a pure logical point of view, it is as impossible to provide a definitive proof that no god can exist as it is to provide one that one god exist. Any attempt will fail miserabily because of the impossibility to provide a proof for its premises at a level.

Things are neat and clear in mathematics. We define a number of axioms, which are to be accepted as is, and from them, we can decline a number of theomems and properties. As we are in a fully abstract world, any set of axioms is valid, provided it brings no self contradiction. And interesting point, is that different sets of axioms can co-exist, if they have nice applications. For example, Euclidian geometry says (a) for any line L and point p not on L, (a) there exists a line through p not meeting L, and (b) this line is unique. It is nicely used for common sense geometry. In Riemannian geometry, we say more or less that for any line L and point P not on L, no line through p not meeting L can exist. Is is indeed againts common sense, but nicely applies for great circles on a sphere and geodesy, and also has important applications in generalized relativity.

When it comes to what we call the real world, the best physicists can do is to provide theories. Their qualities are:

  1. they shall be self consistent (the easy part)
  2. they shall provide interesting results in their domain of validity

For example the good old Newtonian physics is still used to study the movements of planes and satellits. We use relativity when we need to study the solar system (Mercure movements are poorly reproduced by Newtonian physics). We use quantic physics to study the infra atomic scale.

Scientifics require a third rule: the theory should be as simple as possible (the famous Occam's Razor). The reason is not only lazyness, but the more simple the theory is, the easier it is to use it for its interesting results. But the underlying rule behing the Occam's Razos, it that we do not need for a theory to be the reality, we only ask it to correctly describe it.

So using the Occam's Razor to claim that God does not exist, is close to non sense: it uses a tool outside its context. What Occam's Razor can only say is that we do not need any God to describe our world.

So we end in human thoughts proofs. As far as I am concerned, I admit for true that many people cannot live without believing in a God, which should be an evidence that God shall exists. But I also know that other people can perfectly live without any god, which brings the same evidence that god shall not exist.

From that point on, I humbly admit that the existence of God is beyond what human beings can demonstrate, and that religions use to believe in God for a reason.

  • There is a logical refutation of omnipotence using the axioms of Chu spaces, and a logical refutation of omniscience using the axioms of quantum mechanics. It is misleading to claim that this corner of metaphysics is somehow beyond logic and maths.
    – Corbin
    Commented Nov 13, 2023 at 17:24
  • An omnipotent god wouldn’t care about the axioms of Chu spaces. The omnipotent god made up the axioms of Chu spaces in a very convincing way and laughs about you.
    – gnasher729
    Commented Feb 9 at 13:02

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