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

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'?

Solution 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.

Solution 2:

"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.

Solution 3:

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

Solution 4:

I think that this Nazi reasoning given to us by Joseph Goebbles, even in translation, has been read in English print long enough for it to qualify as a common English Phrase.

https://www.jewishvirtuallibrary.org/jsource/Holocaust/goebbelslie.html

If you tell a lie big enough and keep repeating it, people will eventually come to believe it. The lie can be maintained only for such time as the State can shield the people from the political, economic and/or military consequences of the lie. It thus becomes vitally important for the State to use all of its powers to repress dissent, for the truth is the mortal enemy of the lie, and thus by extension, the truth is the greatest enemy of the State.

More of a rant then a phrase but I'm sure it's meaning qualifies as common English knowledge today as a result of the notoriety of the statement.