# Is absence of evidence evidence of absence? **URL:** \ **Category:** Great Debates\ **Created:** [February 20, 2010, 1:18am UTC](https://boards.straightdope.com/t/is-absence-of-evidence-evidence-of-absence/529720 "2010-02-20T01:18:27Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![Superfluous\_Parentheses](https://avatars.discourse-cdn.com/v4/letter/s/8edcca/32.png) [@Superfluous\_Parentheses](https://boards.straightdope.com/u/Superfluous_Parentheses)\ **Post date:** [February 20, 2010, 2:47pm UTC](https://boards.straightdope.com/t/is-absence-of-evidence-evidence-of-absence/529720/21 "2010-02-20T14:47:04Z")
> [@Frank\_apisa](#): > > You cannot use “evidence” to mean “lack of evidence.” Says you. The debate is if that’s true or not. > [@](#): > > There are all sorts of things that “work” for everyday assertions that should not be used in the kinds of debates in which we are engaged here. That does not impact on what I have said. Of course it does. Absence of evidence is only irrelevant if there is no practical way to get evidence. The “kinds of debates” you’re talking about are usually explicitly framed to exclude any expectation of evidence. That does not mean that absence of evidence is irrelevant for the cases where you would expect evidence to be found. > [@You](#): > > > [@Me](#): > > > > For example - I don’t know if someone owns a cat. Statistically, let’s say there’s a 50% chance they’ve got one. I can stick with that 50% or I can go to their house, look in the kitchen etc for cat food, check the house for litter boxes & bowls, look for scratch marks, check for a cat flap etc, and the cat itself. If I find none of those, it’s reasonable to assign a \< 50% probability that they don’t own a cat. > > A lack of evidence for “x”…is NOT evidence that “x” does not exist. You can repeat that all you want but I’m not sure what you mean by it. Do you agree or not that in that situation it is reasonable to reduce the probability of the existence of the cat based on the lack of evidence as provided or not? ---
**Author:** ![Frank\_apisa](https://avatars.discourse-cdn.com/v4/letter/f/47e85d/32.png) [@Frank\_apisa](https://boards.straightdope.com/u/Frank_apisa)\ **Post date:** [February 20, 2010, 2:56pm UTC](https://boards.straightdope.com/t/is-absence-of-evidence-evidence-of-absence/529720/22 "2010-02-20T14:56:17Z")
> [@Anduril](#): > > The LACK of evidence is being acknowledged as evidence of a lack of elephants in the room. :rolleyes: Anduril The proposition being tested is: Is the lack of evidence for “x”…evidence that “x” does not exist. In the elephants in the room situtation…“x” is “there are no elephants in the room.” All you have to do is look in the room…and if there are no elephants…THAT IS EVIDENCE THAT THERE ARE NO ELEPHANTS IN THE ROOM. "X’ is “there are no elephants.” You have plenty of evidence that “x” exists…namely, that “there are no elephants in the room” exists. There is no lack of evidence for “x” in that propositon…so it does not play a part in the question. ---
**Author:** ![Superfluous\_Parentheses](https://avatars.discourse-cdn.com/v4/letter/s/8edcca/32.png) [@Superfluous\_Parentheses](https://boards.straightdope.com/u/Superfluous_Parentheses)\ **Post date:** [February 20, 2010, 3:00pm UTC](https://boards.straightdope.com/t/is-absence-of-evidence-evidence-of-absence/529720/23 "2010-02-20T15:00:28Z")
I also think it’s pretty ironic that someone who wants to stick to such a strict definition of “evidence” would blithely claim there is ANY evidence there’s no elephant in their room. What about a really small one? There’s no evidence elephants can’t be microscopic, after all. ---
**Author:** ![Anduril](https://avatars.discourse-cdn.com/v4/letter/a/c0e974/32.png) [@Anduril](https://boards.straightdope.com/u/Anduril)\ **Post date:** [February 20, 2010, 3:06pm UTC](https://boards.straightdope.com/t/is-absence-of-evidence-evidence-of-absence/529720/24 "2010-02-20T15:06:27Z")
> [@Frank\_apisa](#): > > Anduril > All you have to do is look in the room…and if there are no elephants…THAT IS EVIDENCE THAT THERE ARE NO ELEPHANTS IN THE ROOM. Let’s rephrase this: You look around the room and your senses do not provide evidence of the existence of elephants in the room. The question of the OP: Is that evidence that there are NO elephants in the room? _This is becoming boring. Do I really have to do a step-by-step explanation for you?_ ---
**Author:** ![Superfluous\_Parentheses](https://avatars.discourse-cdn.com/v4/letter/s/8edcca/32.png) [@Superfluous\_Parentheses](https://boards.straightdope.com/u/Superfluous_Parentheses)\ **Post date:** [February 20, 2010, 3:20pm UTC](https://boards.straightdope.com/t/is-absence-of-evidence-evidence-of-absence/529720/25 "2010-02-20T15:20:31Z")
> [@Anduril](#): > > Let’s rephrase this: You look around the room and your senses do not provide evidence of the existence of elephants in the room. The question of the OP: Is that evidence that there are NO elephants in the room? > > _This is becoming boring. Do I really have to do a step-by-step explanation for you?_ Seems obvious to me. It’s almost as obvious to me that if “absence of evidence” really signifies nothing it would be useless to do blind tests on medicine or any other subject. ---
**Author:** ![Frank\_apisa](https://avatars.discourse-cdn.com/v4/letter/f/47e85d/32.png) [@Frank\_apisa](https://boards.straightdope.com/u/Frank_apisa)\ **Post date:** [February 20, 2010, 3:26pm UTC](https://boards.straightdope.com/t/is-absence-of-evidence-evidence-of-absence/529720/26 "2010-02-20T15:26:36Z")
> [@Superfluous\_Parentheses](#): > > Says you. The debate is if that’s true or not. What??? We are testing whether or not a lack of evidence of “x” is evidence that “x” does not exist. “Evidence” does not equal “lack of evidence.” My comments to Anduril cover this. > [@](#): > > Of course it does. Absence of evidence is only irrelevant if there is no practical way to get evidence. The “kinds of debates” you’re talking about are usually explicitly framed to exclude any expectation of evidence. That does not mean that absence of evidence is irrelevant for the cases where you would expect evidence to be found. We are debating whether a lack of evidence of “x” is evidence that “x” does not exist. Fact is…it is not. > [@](#): > > You can repeat that all you want but I’m not sure what you mean by it. When I say “a lack of evidence of “x” is not evidence that “x” does not exist…I mean….a lack of evidence of “x” is not evidence that “x” does not exist. > [@](#): > > Do you agree or not that in that situation it is reasonable to reduce the probability of the existence of the cat based on the lack of evidence as provided or not? In a real sense, NO. Your hypothetical is off target. Consider the question: What is the “x” being tested in your hypothetical…the “x” for which you assert there is no evidence? While thinking about that, consider my hypothetical:: We have absolutely no evidence whatsoever that any life exists on any planet circling the nearest 5 stars to Sol. Do you consider that in any way evidence that there is no life on any of any of those planets? Or do you consider that merely evidence that we do not have any evidence of life on any of those planets? ---
**Author:** ![Frank\_apisa](https://avatars.discourse-cdn.com/v4/letter/f/47e85d/32.png) [@Frank\_apisa](https://boards.straightdope.com/u/Frank_apisa)\ **Post date:** [February 20, 2010, 3:30pm UTC](https://boards.straightdope.com/t/is-absence-of-evidence-evidence-of-absence/529720/27 "2010-02-20T15:30:09Z")
> [@Anduril](#): > > Let’s rephrase this: You look around the room and your senses do not provide evidence of the existence of elephants in the room. The question of the OP: Is that evidence that there are NO elephants in the room? > > _This is becoming boring. Do I really have to do a step-by-step explanation for you?_ YES IT IS EVIDENCE THERE ARE NO ELEPHANTS IN THE ROOM. I have acknowledged that several times. How does that impact in testing whether a LACK of evidence is evidence that “x” does not exist. Do you and SP honestly not see the difference??? ---
**Author:** ![Frank\_apisa](https://avatars.discourse-cdn.com/v4/letter/f/47e85d/32.png) [@Frank\_apisa](https://boards.straightdope.com/u/Frank_apisa)\ **Post date:** [February 20, 2010, 3:31pm UTC](https://boards.straightdope.com/t/is-absence-of-evidence-evidence-of-absence/529720/28 "2010-02-20T15:31:27Z")
> [@Superfluous\_Parentheses](#): > > I also think it’s pretty ironic that someone who wants to stick to such a strict definition of “evidence” would blithely claim there is ANY evidence there’s no elephant in their room. What about a really small one? There’s no evidence elephants can’t be microscopic, after all. I will gladly and freely acknowledge that the lack of evidence that there are no microscopic elephants in the room is not evidence that there are no microscopic elephants in the room. Thank you for the help in making my point. ---
**Author:** ![Frank\_apisa](https://avatars.discourse-cdn.com/v4/letter/f/47e85d/32.png) [@Frank\_apisa](https://boards.straightdope.com/u/Frank_apisa)\ **Post date:** [February 20, 2010, 3:33pm UTC](https://boards.straightdope.com/t/is-absence-of-evidence-evidence-of-absence/529720/29 "2010-02-20T15:33:37Z")
> [@Anduril](#): > > Let’s rephrase this: You look around the room and your senses do not provide evidence of the existence of elephants in the room. The question of the OP: Is that evidence that there are NO elephants in the room? > > _This is becoming boring. Do I really have to do a step-by-step explanation for you?_ No, you just have to understand that what you see to be a step-by-step explanation is merely misunderstanding the problem on your part. Honestly, I am not trying to be obtuse…I am trying to explain something that is difficult…but amazingly clear to me. ---
**Author:** ![Half\_Man\_Half\_Wit](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/half_man_half_wit/32/21766_2.png) [@Half\_Man\_Half\_Wit](https://boards.straightdope.com/u/Half_Man_Half_Wit)\ **Post date:** [February 20, 2010, 3:42pm UTC](https://boards.straightdope.com/t/is-absence-of-evidence-evidence-of-absence/529720/30 "2010-02-20T15:42:58Z")
> [@Frank\_apisa](#): > > The proposition being tested is: Is the lack of evidence for “x”…evidence that “x” does not exist. > > In the elephants in the room situtation…“x” is “there are no elephants in the room.” Nah, x is: ‘there _is_ an elephant in this room’. You look around, see no elephant; hence, there’s absence of evidence for the truth of x. If absence of evidence were not evidence of absence in this case, that would mean that in your assessment of x, nothing ought to have changed after you have looked around; you still have as much grounds to reject as to accept it. Obviously, nobody really thinks so – thus, most people conclude that absence of evidence for the existence of an elephant in the room constitutes evidence of said elephant’s absence; and it’s reasonable to do so, since ‘there is an elephant in the room’ is a particular statement – a singular existential, a little more formal something like ‘there exists x, such that x is an elephant, and x is in this room’ – which is perfectly well decidable through finite observation; only universal statements, like ‘all elephants are in this room’ – ‘for all x, if x is an elephant, x is in this room’ – aren’t: there could always be another elephant not in this room, and all absence of evidence for outside elephants can’t decide the matter. Or, for a different hypothetical, let’s say you postulate a fifth physical force. As a consequence from its behaviour, in a certain particle interaction a certain particle ought to be created (let’s call it the x-particle). So, you set up your experiment to perform the interaction, but fail to detect the proposed x-particle. That means you have an absence of evidence for x-particle production, and, since x-particle production follows necessarily from your theory, you better should revoke it. In this case, absence of evidence (for the x-particle) is, again, evidence of absence (of the fifth force). ---
**Author:** ![Superfluous\_Parentheses](https://avatars.discourse-cdn.com/v4/letter/s/8edcca/32.png) [@Superfluous\_Parentheses](https://boards.straightdope.com/u/Superfluous_Parentheses)\ **Post date:** [February 20, 2010, 3:47pm UTC](https://boards.straightdope.com/t/is-absence-of-evidence-evidence-of-absence/529720/31 "2010-02-20T15:47:33Z")
> [@Frank\_apisa](#): > > In a real sense, NO. Your hypothetical is off target. Consider the question: What is the “x” being tested in your hypothetical…the “x” for which you assert there is no evidence? x = “these people own a cat”. I thought that was obvious. > [@](#): > > While thinking about that, consider my hypothetical:: We have absolutely no evidence whatsoever that any life exists on any planet circling the nearest 5 stars to Sol. Do you consider that in any way evidence that there is no life on any of any of those planets? Or do you consider that merely evidence that we do not have any evidence of life on any of those planets? Consider this: let’s say there IS life on any of those planets. What kind of evidence can we, right now, find that would lead us to conclude it’s there? We can only barely detect planets at all so we might miss more than a few of them, and the only detection we can practically do is a tentative spectroscopic analysis of the atmosphere. I submit that in your hypothetical scenario, we can attribute any absence of evidence to our inability to look for the evidence, and that’s the reason we can’t make any meaningful inference from it. The lack of evidence for life on the moon, for example, is much more meaningful. Seems to me you’re trying to keep a strict linguistic / logical interpretation where “absence of evidence” is tautologically not “evidence”. But the statement “absence of evidence is not evidence of absence” doesn’t work that way: it means “absence of positive evidence for the existence of something isn’t meaningful” and I’m arguing that that’s just not true in most cases. ---
**Author:** ![Frank\_apisa](https://avatars.discourse-cdn.com/v4/letter/f/47e85d/32.png) [@Frank\_apisa](https://boards.straightdope.com/u/Frank_apisa)\ **Post date:** [February 20, 2010, 4:27pm UTC](https://boards.straightdope.com/t/is-absence-of-evidence-evidence-of-absence/529720/32 "2010-02-20T16:27:19Z")
> [@Half\_Man\_Half\_Wit](#): > > Nah, x is: ‘there _is_ an elephant in this room’. You look around, see no elephant; hence, there’s absence of evidence for the truth of x. If absence of evidence were not evidence of absence in this case, that would mean that in your assessment of x, nothing ought to have changed after you have looked around; you still have as much grounds to reject as to accept it. Obviously, nobody really thinks so – thus, most people conclude that absence of evidence for the existence of an elephant in the room constitutes evidence of said elephant’s absence; and it’s reasonable to do so, since ‘there is an elephant in the room’ is a particular statement – a singular existential, a little more formal something like ‘there exists x, such that x is an elephant, and x is in this room’ – which is perfectly well decidable through finite observation; only universal statements, like ‘all elephants are in this room’ – ‘for all x, if x is an elephant, x is in this room’ – aren’t: there could always be another elephant not in this room, and all absence of evidence for outside elephants can’t decide the matter. There is a huge difference between “evidence of a lack”…and a lack of evidence. You might want to consider that or a bit and rethink your argument here. I’ll get back to you more thoroughly on it (got lots to do for the next two hours)…but your reasoning is very faulty because of that difference. A lack of evidence for “x” is not…and never will be…evidence that “x” does not exist. ---
**Author:** ![Superfluous\_Parentheses](https://avatars.discourse-cdn.com/v4/letter/s/8edcca/32.png) [@Superfluous\_Parentheses](https://boards.straightdope.com/u/Superfluous_Parentheses)\ **Post date:** [February 20, 2010, 4:32pm UTC](https://boards.straightdope.com/t/is-absence-of-evidence-evidence-of-absence/529720/33 "2010-02-20T16:32:16Z")
> [@Frank\_apisa](#): > > There is a huge difference between “evidence of a lack”…and a lack of evidence. Nobody’s denying that. > [@](#): > > You might want to consider that or a bit and rethink your argument here. I’ll get back to you more thoroughly on it (got lots to do for the next two hours)…but your reasoning is very faulty because of that difference. Maybe you should follow the arguments a bit closer. > [@](#): > > A lack of evidence for “x” is not…and never will be…evidence that “x” does not exist. Yet even to you, your failure to detect an elephant in your room is evidence that there isn’t an elephant in your room. ---
**Author:** ![Superfluous\_Parentheses](https://avatars.discourse-cdn.com/v4/letter/s/8edcca/32.png) [@Superfluous\_Parentheses](https://boards.straightdope.com/u/Superfluous_Parentheses)\ **Post date:** [February 20, 2010, 4:53pm UTC](https://boards.straightdope.com/t/is-absence-of-evidence-evidence-of-absence/529720/34 "2010-02-20T16:53:07Z")
**Frank apisa** , let’s go back to the elephant. You claim that not detecting an elephant in your room is positive evidence for the non-existence of an elephant in your room. You also claim that this doesn’t violate your argument for some reason since this failure to detect the elephant is - again for some reason - not absence of evidence for the existence of that particular elephant. All the evidence for the existence of the elephant is absent. You’ve seen no elephant, you’ve not detected any elephant droppings, there isn’t a large suspicious shape under a sheet somewhere and you hear no trumpeting. Yet this is according to you not “absence of evidence”. Let’s expand the area a bit. Now let’s say you want to see if there is an elephant in your house. Start with your room; no evidence. Walk to the next room; again, no evidence. etc. Would you consider this lack of evidence for the existence of the elephant? If not, why not? Would you consider this evidence against the existence of that elephant? If so, why? Now switch to an apartment building and repeat the exercise. How large does the area have to be before you switch to the position that there is now suddenly no evidence at all (for or against)? ---
**Author:** ![Contrapuntal](https://avatars.discourse-cdn.com/v4/letter/c/e274bd/32.png) [@Contrapuntal](https://boards.straightdope.com/u/Contrapuntal)\ **Post date:** [February 20, 2010, 4:56pm UTC](https://boards.straightdope.com/t/is-absence-of-evidence-evidence-of-absence/529720/35 "2010-02-20T16:56:20Z")
> [@Voyager](#): > > Example number two. You are an insurance investigator, and one of your policy holders says that a dog he had in the yard for a week during vacation was stolen or escaped. You see food for the dog, and water, and the client claims that a lot of it was eaten. However, investigating the yard yields not one bit of dog poop. What does the absence of that evidence tell you? They live in a [doodie free zone?](http://www.doodiefreezone.com/) ---
**Author:** ![Voyager](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/voyager/32/133_2.png) [@Voyager](https://boards.straightdope.com/u/Voyager)\ **Post date:** [February 20, 2010, 5:25pm UTC](https://boards.straightdope.com/t/is-absence-of-evidence-evidence-of-absence/529720/36 "2010-02-20T17:25:55Z")
> [@PBear42](#): > > **Voyager** , I agree with the distinction you draw in the OP. So, absence of unexpected evidence tells us next-to-nothing. Where I find the absence of evidence most useful is in dealing with anecdotal theories, e.g., astrology, the paranormal and homeopathic medicine. Proponents of such will insist that they’ve seen the theories work, but if one asks for evidence it’s usually thin to nonexistent. Without reasonable evidence, I conclude the theories don’t work. Which is to say, I don’t bother to add them to my toolbox for understanding the world. I understand that someone may eventually come along with reasonable evidence, at which point I would alter my conclusion. Beyond this, we can create situations where we would expect to see evidence if the theories did work, such as collecting information about those born under given signs and comparing different classes. Theories get falsified all the time by absence of evidence against the null hypothesis. **Strinka** , thanks for another good example. ---
**Author:** ![Voyager](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/voyager/32/133_2.png) [@Voyager](https://boards.straightdope.com/u/Voyager)\ **Post date:** [February 20, 2010, 5:35pm UTC](https://boards.straightdope.com/t/is-absence-of-evidence-evidence-of-absence/529720/37 "2010-02-20T17:35:55Z")
> [@Half\_Man\_Half\_Wit](#): > > I think both this and the related (asinine) soundbite ‘you can’t prove a negative’ are somewhat distorted echoes of the impossibility to prove universal statements from (any finite number of) singular (existential) ones. So, both are true when applied to a truly universal statement – that there is no evidence for the existence of black swans does not imply that there aren’t, in fact, any, and similarly, the proposition ‘there are no black swans’ can’t be proven. Both mantras are often erroneously held to be generally applicable, even in cases where one is dealing exclusively with singular statements – which are easily enough proven even if they come in negative formulation, and for which absence of evidence can very well be (compelling, even!) evidence of absence. Let’s not bother talking about proofs. Whatever problems we have with the claim we are discussing, it does not mention anything about proof of absence, only evidence of absence. The number of white swans you’ve observed, and the geographical distribution of the observations, increases the probability that there are none. But doesn’t prove it. ---
**Author:** ![Superfluous\_Parentheses](https://avatars.discourse-cdn.com/v4/letter/s/8edcca/32.png) [@Superfluous\_Parentheses](https://boards.straightdope.com/u/Superfluous_Parentheses)\ **Post date:** [February 20, 2010, 5:44pm UTC](https://boards.straightdope.com/t/is-absence-of-evidence-evidence-of-absence/529720/38 "2010-02-20T17:44:05Z")
> [@Voyager](#): > > Let’s not bother talking about proofs. Whatever problems we have with the claim we are discussing, it does not mention anything about proof of absence, only evidence of absence. The number of white swans you’ve observed, and the geographical distribution of the observations, increases the probability that there are none. But doesn’t prove it. Yes. The “problem” is that you cannot have any direct positive evidence of the non-existence of anything. The best you can ever do (unless the item in question is logically impossible) is try to get evidence _for_ its existence. The “debate” is whether you can **ever** say that having failed to find evidence should influence the probability of the item (not) existing. So far, the only person in this thread who claims it’s not possible to do that has shown a remarkable flexibility in the definition of “lack of evidence”, some plain assertions, and not much else. Unless **Frank** comes back with a clearly reasoned argument, I consider the matter resolved. ---
**Author:** ![Voyager](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/voyager/32/133_2.png) [@Voyager](https://boards.straightdope.com/u/Voyager)\ **Post date:** [February 20, 2010, 5:49pm UTC](https://boards.straightdope.com/t/is-absence-of-evidence-evidence-of-absence/529720/39 "2010-02-20T17:49:37Z")
> [@Frank\_apisa](#): > > The “expected” and “unexpected” qualifiers does not change things in any way in that regard…and appear to me to be gratuitous in furtherance of some other agenda you may have for this question. (Can’t imagine what that could be!😕) First, are you confusing things that would contribute to a proof of nonexistence with things that are just evidence of nonexistence? The logic I know of does not discuss evidence. Second, do you really not see the difference between expected and unexpected evidence? We can consider the things beyond which we know nothing as a kind of event horizon. At the moment, I have no evidence for or against the contention that my brother in Boston had eggs for breakfast. The absence of evidence for this says nothing about the truth of the proposition, because it is outside my event horizon. However, the absence of eggshells in the trash is evidence that my wife didn’t have them. Not proof - evidence. I’m responding to posts in order, so maybe sometime later someone has helped you with this point. ---
**Author:** ![Frank\_apisa](https://avatars.discourse-cdn.com/v4/letter/f/47e85d/32.png) [@Frank\_apisa](https://boards.straightdope.com/u/Frank_apisa)\ **Post date:** [February 20, 2010, 5:51pm UTC](https://boards.straightdope.com/t/is-absence-of-evidence-evidence-of-absence/529720/40 "2010-02-20T17:51:13Z")
> [@Superfluous\_Parentheses](#): > > Nobody’s denying that. > > Maybe you should follow the arguments a bit closer. I am following it very closely, thank you. > [@](#): > > Yet even to you, your failure to detect an elephant in your room is evidence that there isn’t an elephant in your room. The point being the difference between a “lack of evidence” and “evidence of a lack.” The fact that you look around and see no elephants (I am leaving aside your microscopic elephants or invisible elephants)…is evidence that there are no elephants. We are not working with a lack of evidence here. We have evidence…it just happens to be evidence that there are no elephants in the room. This is quite different from the question of whether or not there is life on any of the planets revolving around the 5 nearest stars to Sol…where we have absolutely no evidence in either direction. The “evidence of lack” (which IS evidence) is what persuades me there are no elephants in the room…not any lack of evidence. I am sorry you are having so much trouble with this. Wikipedia, which I hardly ever cite, does an excellent job of discussing the lack of evidence fallacy…which is often called the argument from ignorance or the argumentum ad ignorantiam. You might want to read it. > **[Argument from ignorance](https://en.wikipedia.org/wiki/Argument_from_ignorance)** > > Argument from ignorance (Latin: argumentum ad ignorantiam), or appeal to ignorance,\[a\] is an informal fallacy where something is claimed to be true or false because of a lack of evidence to the contrary. > The fallacy is committed when one asserts that a proposition is true because it has not yet been proven false or a proposition is false because it has not yet been proven true. If a proposition has not yet been proven true, one is not entitled to conclude, solely on that basis, that it is fals... [Previous page](https://boards.straightdope.com/t/is-absence-of-evidence-evidence-of-absence/529720.md?page=1) [Next page](https://boards.straightdope.com/t/is-absence-of-evidence-evidence-of-absence/529720.md?page=3)