Is there a common English phrase for the 'so absurd it must be true' logical fallacy?

Question

There are various common (often Latin) phrases for various logic fallacies, such as post hoc ergo propter hoc, argumentum ad populum, slippery slope fallacy, etc. Is there a common phrase used to describe the fallacy of saying that because a claim seems so unusual or specific, it must be true, because 'nobody would ever make something that unusual up'?

Answer 1

The biggest problem in finding a technical fallacy is that "absurd", in this context, isn't detailed enough. Why is it absurd? The idea that any absurd thing could be believed if it was simply absurd enough is not really true.

The idea of arguing something as true because no one would make it up is close to these fallacies:

• appeal to authority — using the speaker or source as evidence that it must be true
• proof by verbosity / proof by intimidation — using lots of variously connected evidence or jargon that overwhelms the listener such that it is easier to just assume that the proof is correct
• misleading vividness — using supreme detail in one example to form an incorrect generalization
• Big Lie

Strangely enough, the last is pretty darn close and is described as:

a lie so "colossal" that no one would believe that someone "could have the impudence to distort the truth so infamously."

If you notice the quotes in that quote, you may wonder who coined the term. It was Adolf Hilter in his book Mein Kampf. In a certain sense, this Big Lie is an appeal to authority mixed with a strong pull on assumed morality.

Many tend to think of an appeal to authority as the style of bringing in a football player to advertise footballs: Since the player uses football, surely he knows which are best. But appeal to authority also includes what we are talking about here. Trying to list the steps it would look something like this:

1. Idea
2. Idea appears absurd
3. The person claiming Idea couldn't/wouldn't lie/imagine such an absurd thing
4. Therefore it is not absurd
5. Therefore Idea is plausible/true

The 3-4 step is the appeal to authority. Using English, these are all appeals to authority:

Well, they couldn't possibly make something like that up

All of humanity isn't clever enough to think of something like that

Sam is a terrible liar; therefore this isn't a lie

In conclusion, most "so absurd it must be true" arguments are likely to include one of these somewhere. They probably have other problems, too, considering how absurd they are. The specific term Big Lie is appropriate for someone who actually created such an absurd argument and is using it against the people who consider it too absurd to doubt.

Answer 2

There is no such fallacy. The nearest I could get was:

Appeal to Wonder

This fallacy occurs when someone declares that any statement which appears too novel, too wonderful or astounding, must be false, simply because of the sensation of wonder or amazement the statement causes. There is nothing wrong with this sense of wonder causing us to take pause, and express doubt, but to rely solely on this sensation as a rebuttal is a logical fallacy. As Carl Sagan stated in Candle In The Dark, science (i.e. rational thinking) is a blend of wonder and skepticism, neither alone is sufficient

Answer 3

While it doesn't touch on the "absurd" portion, a related concept is the exception that proves the rule in it's more modern, sardonic, "incorrect"† sense.

† ("Incorrect" according to Fowler a century ago, though the modern "nonsense" version is the only way I've ever actually heard it in day-to-day life.)

Answer 4

I believe [sic] that you are after a higher concept, such as dogma.

It does not fit all the attributes that you have prescribed, however it describes how one could come to accept propositions that are or seem to be unbelievable, incredible or fantastic.

On the other hand, I don't believe that credibility of such statements grows intrinsically from their unusualness. I think that your criteria: "it must be true since no one would make this up." is an afterthought, a reasoning (and yes, that is fallacious).

The original statement is not fallacious by itself - for example, such statement could have been: "It rained frogs". By itself it does not make me believe that it is true just because it sounds highly unlikely (or impossible); on the contrary, without any context I am more inclined to reject the statement as false. Still, it is a statement - either true or false. It contains no intrinsic fallacy and we can accept it either as assumption (used in consequent reasoning) or axiom (postulate) or as dogma.

It is fallacious to defend its truth value by saying "it must be true since no one would invent such a thing".

Answer 5

"Truth is stranger than fiction" is a common English phrase, and implies that something outlandish is probably true. Admittedly it is not exactly what the questioner sought.

Answer 6

There is a quotation (from St Augustine?), Credo quia absurdum. But it's onluy used in theology, not logic.