(Please note that this question is a hypothetical example with a premise that can't be challenged. When I say this fictitious principal sabotaged a test, and a reporter knowingly lied about it, that's exactly what happened. The question is "What kind of fallacy would we have IF the premise is exactly as it was described.")

Imagine a school with an unusually high parental involvement rate. Parents even collaborate with teachers in choosing curricula and devising tests, which are scored with the help of a computer.

One day, the principal sabotages a test without telling anyone. People are surprised when students score unusually low, and some suspect foul play. Local activists begin complaining about a "scam."

A local newspaper reporter writes an article about the situation. He assures readers that the students scored low because they're getting too much recess. (a lie) The solution is to shorten recess and make students stay after school for special tutoring. (Is this sentence a fallacy, or just a worthless "opinion"?) He says, "If there had been a scam, some teacher or parent would have blown the whistle." (a lie and/or fallacy?)

The reporter knows that a) the principal sabotaged the test, and b) teachers and parents knew nothing about it. So he's effectively lying when he implies that teachers and parents would have knowledge of a scam.

His logic is as follows:

Teacher/Parent blows the whistle = scam

No one blows the whistle = no scam

Again, teachers and parents can't blow the whistle if they don't know what's going on behind their backs.

What kind of fallacy has this reporter committed?

  • 1
    What I wonder is if lying or deception is a logical fallacy or an ethical failing. Does everything have to be viewed as a logical fallacy? – Frank Hubeny Aug 31 '18 at 21:15
  • Of course not; one of my goals is to compile a list of all the "crap" that can not be classified as fallacy. In that spirit, the example in my question might be nothing more than an "implied lie." However, it sounds fallacious to me. It sounds like an invalid argument...IF there had been a scam, someone WOULD HAVE reported it. – David Blomstrom Aug 31 '18 at 21:34
  • 1
    If there is a fallacy, i.e. mistake in reasoning, what reporter knows is irrelevant. The argument is: if there was a scam someone is likely to expose it, it was not exposed, therefore there was likely no scam. The argument is pragmatically valid. Whether the premise is true depends on circumstances beyond what is described, but in any case the conclusion is consistent with the description, "the principal sabotages a test without telling anyone" sounds unlikely. – Conifold Sep 1 '18 at 4:52
  • Oops, I guess I should have worded my question more carefully. I posed a hypothetical example in which the principal DID sabotage a test (something that has been known to happen, by the way). There are no circumstances beyond what I described; the question is what it is. So the premise is solid; all we can examine here is the argument. In that spirit, your second and third sentences might answer the question. – David Blomstrom Sep 1 '18 at 5:21
  • But if he lies, he does not commit a fallacy, no? Erroneous thinking is not lying. – rus9384 Sep 1 '18 at 14:24

I hate to be too hasty in answering my own question, but the hasty generalization fallacy sounds like a possible candidate.

Hasty generalization occurs "when someone draws expansive conclusions based on inadequate or insufficient evidence." In other words, they jump to conclusions, overlooking potential counterarguments in the process.

However, there's a catch: In this example, there's no shortage of evidence; the whole truth is known - to the principal and the reporter. The article that appeared in the newspaper is thus a lie...similar to many fallacies.

Conifold's comment above introduces an interesting twist: The argument that appeared in the newspaper omits the truth. Therefore, the omitted truth arguably isn't part of the fallacy; we have to judge the fallacy on its own merits.

So it sounds like we have a compound problem involving 1) a lie of omission and 2) a fallacy.

But this question is starting to sound like a paradox. When someone reads the article, are they seeing a fallacy or a lie (or maybe both?)?

This is what the reporter wrote in my hypothetical example:

If there had been a scam, some teacher or parent would have blown the whistle.

Does that qualify as a lie? In real situations similar to this one, people sometimes blow the whistle and sometimes don't. There's no one-size-fits-all formula.

EDIT: On rereading this, I think this DOES qualify as a lie, based on the word would. The reporter should have said "might" have blown the whistle.

Yet another possible candidate is the slothful induction fallacy, which is ironically the inverse of hasty generalization. Slothful induction occurs when someone ignores sufficient logical evidence indicating a particular conclusion is true.

But this turns into another catch-22: The reporter didn't ignore "logical evidence;" he deliberately omitted the truth. Or, for all practical purposes, would omitting the truth be the same as ignoring logical evidence in this case?

  • I think there two separate issues here. One is whether the argument on its own is fallacious. The second is whether the reporter has committed a fallacy. The former can be answered without any reference to the reporter. The latter is a little confusing due to the fact that the reporter was lying. I'm inclined to think they haven't committed a fallacy because they said what they did with an intention to deceive, and there was no genuine attempt at reasoning. Anyway, this lying bit might distract from the fallacy issue -- is it crucial to your question? – Eliran Sep 1 '18 at 10:20
  • Good question. I tried to reduce this to a simple hypothetical example in order to avoid confusion. I'm almost tempted to ask two separate questions, featuring a lying reporter and an honest reporter. ;) But I don't think I want to start hacking away at this question. That would just make things more confusing, and I think it's a pretty good brain-teaser as it is. I've learned a lot by pondering it. – David Blomstrom Sep 1 '18 at 14:08
  • I just realized that the word "would" does make the reporter's statement a lie. I edited my question to reflect that. – David Blomstrom Sep 1 '18 at 14:15
  • Although I think it is rather argument from ignorance, I am beginning to see the significance of your example. +1 – Frank Hubeny Nov 30 '18 at 20:05

To some degree the example is a 'base-rate fallacy', although in the opposite of the usual direction. It ignores the possibility that a very small number of people might know the cause, and that therefore they could all be corrupt. (Usually this fallacy ignores a small likelihood applied to a large number of instances, instead. But the math, and thus the logic, is the same either way over.)

It assumes because there are a lot of people affected, the cause could not escape them all. But the number of people affected is not the base to which the likelihood of corruption should be applied, the number of people causing the scam is.

In this case the scam proceeds from a single person with a lot of power, rather than from a number of people who would have to communicate and leave traces that could be noticed.

But that explanation does not have anything in particular to do with your title...


The fallacy may be the argument from ignorance. The Logically Fallacious site describes it as

"The assumption of a conclusion or fact based primarily on lack of evidence to the contrary."

Here are parts of the situation that fit such a fallacy:

  • There is a "premise that can't be challenged" because "teachers and parents can't blow the whistle if they don't know what's going on behind their backs". Those having to judge the situation are ignorant of the available evidence.

  • People are asked to make a decision they perhaps otherwise would be reluctant to make. They are being asked to support the principal's desire "to shorten recess and make students stay after school for special tutoring." This motivates the principal and reporter to present the argument and in addition to the argument lie.

  • There are people who doubt the argument: Local activists begin complaining about a "scam." The existence of these doubters further motivates the principal and reporter to make the fallacious argument and lie in the process. These doubters or enough others need to be convinced for the shortened recess policy to succeed.

The fabrication itself is a lie. It is an ethical failing, but it is not part of the fallacy. The fallacy is in the argument itself and it requires ignorance of evidence to succeed. The argument would be fallacious even if there were no ethical issues involved.

Douglas Walton describes the social significance of arguments from ignorance. The following are only some examples he considers:

  • anti-communist witch hunts (pages 3-4)
  • zero tolerance policies in a war on drugs (pages 5-7)
  • allegations of sexual abuse (pages 7-10)

In all of those cases there are social motivations that encourage people to act or accept the actions of others on their behalf without being able to tell if the actions are justified because of the lack of evidence. Arguing to take the action in spite of resistance to do so is a motivation for those promoting the action to present arguments from ignorance.


Bennett, B. "Argument from Ignorance", Logically Fallacious https://www.logicallyfallacious.com/tools/lp/Bo/LogicalFallacies/56/Argument_from_Ignorance

Walton, D. (1996). Arguments from ignorance. Penn State Press. (See Walton's papers and books.)

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