What is the term for allowing an implausible scenario in order to be as generous as possible to the claim one is about to knock down? Example:

Acme Acres recorded 2,000 births last year, but the town has only 500 women. Even if they are all of child-bearing age and each had two deliveries last year, it is still virtually impossible that they gave birth to 2,000 babies. Either out-of-towners were flocking to Acme Acres to deliver or the statistic is wrong.

It's a little like "giving the benefit of the doubt" "for the sake of argument", but I don't think "doubt" is the right word here (the allowed scenario is almost certainly false). There should be a precise term or expression from this kind of argumentation, at least a Latin one from law or a Greek one from rhetoric.

  • 2
    If you take an argument to its logical conclusion, you can bury the argument by showing that the result is foolish. Reductio ad Absurdum. Jan 24, 2021 at 18:18
  • I cannot find the Latin for "Some of those girls will never walk again" but perhaps someone will help.
    – Elliot
    Jan 24, 2021 at 19:50
  • 1
    Does this answer your question? Term for the "extreme-extension" version of a straw man fallacy? Jan 24, 2021 at 20:01
  • @EdwinAshworth No. I'm not appealing to extremes in my argument, nor I am making a strawman of the the claim I'm rebutting. If anything, I'm trying to to be charitable to it to show it still isn't valid even taken in the best possible light.
    – bongbang
    Jan 24, 2021 at 20:15
  • The official data you give is 'Acme Acres recorded 2,000 births last year; the town has 500 women'. You introduce the straw man fallacy as a hypothesis to attack (The 500 women averaged 4 births in the last year). <A straw man fallacy: when someone takes another person’s argument or point [here the data], distorts it or exaggerates it in some kind of extreme way, and then attacks the extreme distortion, as if that is really the claim the first person is making.> [Excelsior College] ... Jan 25, 2021 at 14:43

5 Answers 5


Actually, you are not allowing anything but reasoning on a limit case possibility. As a type of reasoning I would call it "disproof of the conclusion on the basis of the impossibility of a limit case".
I don't think there is one word term for this sort of reasoning; at best, there might be a rather long phrase.

  • The allowance is to put the claim in the best possible light before rebutting it, which is more conclusive than otherwise. It's like beating an opponent with a weapon while you're unarmed. My example is stronger, not weaker, with the italicized part.
    – bongbang
    Jan 24, 2021 at 19:26
  • @bongbang I see, I didn't get your question right.
    – LPH
    Jan 24, 2021 at 19:35

The common English phrase used is for the sake of argument.

for the sake of argument phrase As a basis for discussion or reasoning. ‘suppose, for the sake of argument, that this is the legal position’ -Lexico


I believe you have a kind of mashup of procatalepsis and reductio ad absurdum.

The OED defines procatalepsis as:

A rhetorical figure by which an opponent's objections are anticipated and answered

and reductio ad absurdum as:

The practice of demonstrating the falsity of a hypothesis, principle, etc., by showing that the consequence of assuming it to be true is something absurd or contradictory

Proposition: It's impossible that 500 women birthed 2,000 babies last year.

Anticipated objection: 500 women averaging two babies a year = 2,000 births.

Implied absurdum: Assuming women could average two births per year, picture the population count!

Conclusion: Either out-of-towners were flocking to Acme Acres to deliver, or the statistic is wrong.

  • Unanticipated objection - math much?
    – Phil Sweet
    Jan 25, 2021 at 1:35

This is a argument by reverse implication.

Forward implication:

  • P1: A implies B
  • P2: A
  • therefore B.

Reverse implication:

  • P1: A implies B
  • P1’: not B implies not A (same meaning)
  • P2: not B
  • therefore not A

Expressed in words:

A: there are 500 women resident in Acme Acres B: the maximum number of births (for 500 women in a year) is less than 2000

P1: 500 women implies a maximum number less than 2000 births

P2: there were 2000 births

Therefore, there could not have been 500 women giving birth in Acme Acres who were resident in Acme Acres. There had to have been more.

This logic here is obviously somewhat condensed. However, the challenge in this kind of argument is to construct the implication statement so that it gives a binary value when all you have are numbers and plausible estimates.

Personally, I would refer to this as “making an extreme argument”, but I don’t think it’s special enough to have a special name. Modern symbolic logic has made a lot of the old Latin and Greek nomenclature obsolete.


By accepting an implausible argument or unlikely assertions you are giving your opponent enough rope to hang himself

give (one) enough rope

If you give people the opportunity to do something wrong or detrimental to themselves, they will usually do it; one does not need to interfere to bring about someone's downfall. The full version is, "Give (one) enough rope, and (one) will hang (one)self."

"Don't interrupt him with questions. Just let him keep talking and he'll incriminate himself. Give him enough rope and see what happens"

Free Dictionary

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