My question was inspired by this question here. Essentially for questions with an impossible negation it was advised that the best approach is to say we don't know or simply give a summary of current knowledge on the subject.

What I would like to know is if there is any guideline for considering a hypothesis over alternates.

Perhaps showing answers to similar questions or situations could be one approach, but is not reliable and probably should not be used as support.

If there is an absence of evidence and no way to verify either way should we simply say that we do not know, or is it perhaps better to outline the most likely answers and give reasoning, as these can then be debated which aids in our quest for knowledge?

I have added some example questions which I hope illustrate my point with more clarity.

Is there a shadow government exerting control over global matters?

This question is not asking if organizations exist attempting to do that, but whether or not an organization has successfully done so and is secretly running the world. It is interesting because it should be possible to investigate and establish an answer, except that most people simply don't have the means to do so.

Since a reliable investigation, scientific or otherwise is out of the question, then is using reasoning based on what we do know acceptable?

For example:

  1. With the worlds most powerful countries continually being manipulated, with the amount of people privy to this knowledge someone would have come forward.

  2. There is poor evidence of collusion on such a grand scale. The worlds most powerful countries often disagree on key matters

  3. If ultimate control is the key, why not do it in a more direct way? Depending on how long a shadow government may have been in control, would it not have the resources to take more direct control?

Problems with such arguments are that they are not exactly backed by hard evidence. For answer 1 you can show that through history conspiracies tend to be exposed, it would be easy enough to find evidence for 2 and 3.

Counter arguments could be that the organization is powerful enough to prevent exposure through death or threats, that the seeming lack of collusion is orchestrated to keep people from learning the truth

Such claims becomes increasingly complex, so if Occam's razor is applied than my examples answers would be adequate for such a question?

Another example question

Do donkeys kill more people than airplane crashes?

Perhaps. The Snopes article linked to states that we have insufficient data on deaths caused by donkeys to reach a firm conclusion.

Based on what we do know:

  1. Airplanes are statistically one of the safest methods of travel.
  2. Donkeys are a very passive animal, exceptionally rarely attacking humans.
  3. Even if a Donkey were to attack a human it would likely not be with the intention of killing and would stop if the human were to flee.

It would seem then that for a donkey to directly kill a human would be an exceptionally rare event, not often observed and thus occurs substantially less than fatalities by plane crash.

In this case evidence of absence is a reasonable indicator, combined with the knowledge we have about plane crashes and donkeys.

Are musicians more likely to die when reaching 27 years of age?

The so called 27 club. There is no hard data or research on this particular issue, although when musicians are taken as a whole deaths at 27 are not significantly high. It seems there is no reason to assume something unique to musicians that would make a death more likely at a specific age.

Potential reasons why people might think this:

  1. A string of coincidental deaths at age 27 causing any further musicians dying at age 27 to be noticed more.
  2. Potentially higher use of dangerous substances associated with a rock lifestyle may lead to earlier deaths.

None of my example questions have been asked, although related questions have been. In my example answers I have not really checked or properly sourced them, however I hope they serve as examples even if incorrect.

Should these kinds of questions and answers simply not be allowed? I would argue that they should be allowed as example answers such as the above still aid in reaching a conclusion after a skeptical analysis.


2 Answers 2


It's quite hard to give a generally valid answer to your question, because the risk is that the debate is simply moved to "what questions are about impossible negations?".

I think that we should always answer in the spirit of the site, which is: bring evidence to the table. I do not think that the correct spirit is: find the ultimate truth.

For example, I think that all of these are acceptable answers:

  1. "We don't know as there is no consensus about the answer: [link to expert opinion/papers that prove no consensus]"

  2. "The problem has not been addressed in scientific literature, thus the question cannot be settled for the moment, however the following evidence provides a partial answer [link]"

  3. "We don't know whether there is a teapot in orbit between here and Mars, however Bertrand Russel has [something to say] about this hypothesis. Furthermore, the [list of known near-Earth objects] does not contain teapots."

Also, I would consider as off-topic or not constructive questions that cannot, in principle, be (ever) answered with evidence. For this reason, for example, questions about motivations are not allowed. For this very reason I disagree with Oddthinking that we should have a boilerplate answer for such questions. They should simply not be allowed.

  • I don't understand your first statement...if discussing a question with an impossible negation why would you then start questioning if it did or not? There are certainly questions that can likely never be answered with evidence, or not in our life time, but that doesn't mean less direct evidence and reasoning can not be of use. Nov 18, 2011 at 2:39
  • Also, the spirit should be a quest for knowledge. Every question, no matter how impossible will have evidence, however indirect it may be. In which case where do you draw the line with indirect evidence and inferring the most reasonable hypothesis? Nov 18, 2011 at 3:48
  • Sorry for not being clear. I still do not believe motivation questions should be allowed. I was thinking more like these questions: Secret colony on Mars, Go as war-decider, Coke executive story.
    – Oddthinking Mod
    Nov 18, 2011 at 6:17
  • The colony on mars is a great example, and go is as well to a lesser extent. Would the coke question not simply rely on anecdotes, so not really ever be useful on this site? Nov 18, 2011 at 7:30
  • @sonny the point is that questions should be decidable with facts, at least in theory. Questions for which we are merely "unlikely" to have an answer, are perfectly allowed and welcome here, as any other SE site. Finally any subjective "measure" of sincerity or usefulness is not something we should ever adopt.
    – Sklivvz
    Nov 18, 2011 at 8:28
  • @odd why is the coke manager any different from all other historical/literature/citation questions?
    – Sklivvz
    Nov 18, 2011 at 8:31
  • @odd all the questions you mention are perfectly answerable and there is absolutely no problem with them. They are not impossible negatives at all.
    – Sklivvz
    Nov 18, 2011 at 8:37
  • @Sklivvz, it is a question of scale. Some questions are not able to be directly answered with facts, so then it becomes a question of to what extent do we use indirect facts or reasoning. The colony on mars question for example relies on indirect evidence, as first hand evidence is unavailable. Nov 18, 2011 at 9:41
  • @SonnyOrdell Not a question of scale. If there were a colony on Mars, it would be perfectly answerable. The point is that you need to assume there is no colony before you can state that answers can only "rely on indirect evidence". But how can you support your assumption?
    – Sklivvz
    Nov 18, 2011 at 9:50
  • @Sklivvz Except that isn't what really happens on this site. People post questions about claims. The person posting the question is not supporting the claim, but asking if it is reasonable or likely. Hence in answers explaining why or why not, scale becomes relevant. Explaining why it makes sense to assume there is no colony on mars is different to why fire can cause paper to burn. One is directly verifiable and reproducible, the other relies on indirect evidence and reasoning. Nov 18, 2011 at 9:58
  • @SonnyOrdell my point is that you are asking us not to allow questions based on mere assumptions. I don't think we should do that.
    – Sklivvz
    Nov 18, 2011 at 10:02
  • @Sklivvz, I am asking to what extent indirect evidence and reasoning should be used in such questions. There is no question that such questions are already allowed. Nov 18, 2011 at 10:05
  • @SonnyOrdell that fundamentally depends on what evidence you can find. Sometimes, there is simply no good evidence. The important thing is generally to look at all the available evidence (direct, indirect) and present it appropriately. A good, referenced partial answer is always acceptable. In the worst case scenario, if you can only bring tidbits to the table, it is customary to put up a CW answer for everyone to contribute to.
    – Sklivvz
    Nov 18, 2011 at 10:13
  • @Sklivvz so then in your opinion, the example question and example answers in my actual question are fine with you? Nov 18, 2011 at 10:38
  • @SonnyOrdell it depends on the evidence available. In principle, though, I see nothing wrong with the questions and answers you propose. I see nothing wrong with a weak answer if it's clearly stated that it is as such -- the requirement is only evidence.
    – Sklivvz
    Nov 18, 2011 at 10:45

Edit: This answer has significantly changed due to examples being provided and in response to Sklivvz's answer.

27 Club: there is no good reason why a study could not be made to answer this question with a True or False answer. I do not see this question has an impossible negation. Conjecturing that drugs may cause more deaths in musicians at 27 is completely unhelpful if/when it turns out that they do not die earlier. Conjecture like that is what Yahoo.Answers - in fact, most of the rest of the Internet - is built upon, and why it is completely untrustworthy.

Donkeys: again, there is no good reason why a study could not be be made to answer this question with a True or False answer.

Shadow Government: Now, we get to the philosophically interesting one. Either:

  • It is true, and someone can prove it! Hooray!
  • It is false, and someone can prove it! I cannot see how they could, but I have been surprised by the ingenuity of people here before. Hooray!
  • It is true or false, but no-one can prove it yet. Ideally, the question would stay open until some evidence was found. Alternatively, it could be answered that some expert has looked for the evidence and found it lacking either way.
  • It is false, and no-one will ever be able to prove it. This is where it is tricky.

That tricky final case could be addressed with conjecture, but it was conjecture that got us into this situation in the first place. Without evidence, I see little value in conjecturing about it - except as an exercise in extracting predictions that could then be tested.

The same logic could be applied to these questions, which I suggested in a comment on Sklivvz's answer: Secret colony on Mars, Go as war-decider, Coke executive story. Each of these answers might be true, but if (as I suspect) they are false, that could (sans surprising twists of logic) never be shown.

An idea I continue to be considering is to allow people to put a CW placeholder answer that points to a meta-question with a high-quality general-purpose answer.

The referenced answer would explain:

  • how to deal with conjectures that have no evidence,
  • the idea of provisionally accepting a position,
  • the power of Ockham's Razor,
  • the need for extraordinary evidence for extraordinary claims,
  • the burden of proof

... basically what it means to take a skeptical position.

Such an answer would be a second-grade answer, in that it wouldn't be as nearly valuable as a direct True/False answer, but it would allow some of the unanswered claims to get an answer when (consensus would suggest) they are both false and unable to ever be proven false.

  • "Is there a shadow government exerting control over global matters?", this is quite easily answered by taking the conspiracy theory and debunking its mechanisms. Of course there's still the "Is there an undetectable conspiracy secretly controlling our lives?" version which is easily answered by linking to classic paranoia cases. ;-)
    – Sklivvz
    Nov 18, 2011 at 14:43

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