The "useless negative" problem

Question

The "useless negative" problem (a term I just coined because I honestly don't know how else to label it) refers to an issue that I see cropping up on a lot of questions: Questions which are, at their most fundamental level, a yes/no question, where the "yes" side would prompt answers which are good, useful and interesting, but where the "no" side would not.

To my knowledge, yes/no questions are generally permitted across the SE network, especially since such questions tend to have an implicit "if yes, why, and if no, why not?" included. However, one basic principle in Islam (I believe it's considered fundamental to the majority of (if not all) schools and sects) is the idea of "default allow": If there is no evidence prohibiting, or mandating, a particular action, it is considered permissible and optional. Schools may differ over what does and does not count as "evidence," but the general principle remains.

What this means is that a lot of questions tend to fall into the "useless negative" problem as described above. For example,

• Is such-and-such haram?

  Positive: Yes, it's haram because of evidence, evidence, evidence.
  Negative: There is no evidence concerning it, so no.

• Is there any Islamic basis for such-and-such?

  Positive: Yes, there are numerous reports of evidence, evidence, evidence.
  Negative: There is no evidence concerning it, so no.

• Is such-and-such mandatory?

  Positive: Yes, there is evidence, evidence, evidence mandating it.
  Negative: There is no evidence concerning it, so no.

In each of the above questions, the positive answers are all good answers. They're clearly on-topic, useful and interesting. They provide evidences and are generally the types of answer we want on this site.

The negative answers, on the other hand, are inherently bad and uninteresting; they're just saying the same thing every time, "No, because I know no reason to say yes," with little to no room for elaboration. And in many cases, the negative answer may well be the most correct answer.

The fundamental problem with the "useless negative" is that it effectively requires trying to prove a negative; the only way to authoritively do such is to know all possible evidences (or at least all acceptable evidences in any particular school). However, since the negative claim itself requires only ignorance of the evidence, anybody can honestly post the answer regardless of their own level of knowledge.

Such answers are fundamentally useless.

Given that we, as a site, are generally trying to promote answers which cite sources and give references, any good answer should have sources and references to actually cite. However, leaving these "useless negative" questions unanswered doesn't really help matters; even if the negative is the most correct opinion, any weak evidence (one that may not even be accepted by any schools) would be the answer that gets posted.

So the question lies thus: How should we deal with such questions and/or answers?

Answer 1

Thanks for framing the issue. A fundamental issue with having a general rule for these types of questions is that we don't know in advance whether a question has a positive or negative answer. I suppose one could judge whether the answer, if negative, is "useless" or not, but this is upstream. If I ask for the basis behind a certain practice, and it turns out there is something in the texts, then I wouldn't want that question to be shut down because the answer, if negative, is useless.

With that in mind, I think the decision should be case-by-case. Anybody asking these questions should provide as much context as possible, and depending on how realistic it is and how widespread it is whether there is a source for the claim we can make a decision about whether to keep it open or specify it further or close it.

Answer 2

One way is to enforce the rule there needs to be a reason for them to believe it. Similar to with the Skeptics rule in that every claim has to be notable.

However, these questions often pop up all over the world, and what would make a decent answer is "No, and (this Islamic authority/figure) has said such." It does not necessarily have to be a strong authority, but proof of consensus somewhere. A group of Islamic people practicing it might suffice. The stronger the authority/knowledge of this group, the better the answer.

Answer 3

There are meaningful ways of answering such questions, more than just saying yes/no:

Absence of evidence

From Negative evidence on Rational Wiki:

Negative evidence occurs when an absence of evidence is actively found when actively looking for something. (Don't see your car in the garage? It's probably not in the garage.) An appeal to ignorance occurs when an absence of evidence is found when nobody has done any looking! (Maybe you should actually walk to the garage and check, before assuming your car isn't there.)

Thus, to find negative evidence, we can (a) identify a likely consequence (e.g., there would exist a scholarly fatwa claiming that XYZ is haram), and (b) find no evidence of the consequence, despite efforts to find such evidence.

In these circumstances, we can perform a literature search (e.g. searching various fatwa sites) and document our efforts. This allows the reader to distinguish between "we did not observe this, because we did not try" and "we did not observe this, despite our efforts".

Absence of evidence, or the failure to observe evidence that favors a hypothesis, is evidence against that hypothesis. This is because we are significantly more likely not to see evidence for a hypothesis when it is false than not to see it when it's true ... (Rational Wiki)

Example: Here's an example from travel.SE of how to apply an "absence of evidence" argument:

Question: Can I see the American Airlines upgrade list on their website?

Answer: ...after an exhaustive search through discussions at FlyerTalk and Milepoint, blog posts at The Cranky Flier and Boarding Area, and articles at other places which report on the vagaries of AAdvantage and its tools, I'm prepared to say that as of May 2015 the answer is still no...

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There seems to be some other methods we could use:

Argument from authority

We demonstrate that reasonable, knowledgeable scholars believe that "no evidence exists". We can do this by citing references, or just wait until such a scholar decides to answer the question themselves.

A logically valid argument from authority grounds a claim in the beliefs of one or more authoritative source(s), whose opinions are likely to be true on the relevant issue. ... it is likely to be true, rather than necessarily true. (Rational Wiki)

The fact that these questions can be authoritatively answered by a scholar, may even attract scholars to the site.

Reductio ad absurdum

There's also reductio ad absurdum, which can be applied in the context of Islam, e.g.:

• "Is such-and-such haram?" "If it were then XYZ would also be haram. But Prophet Muhammad did XYZ [see hadith]. So no."

• "Is such-and-such mandatory?" "If it were, then we wouldn't be able to pray. So no."