What is a phrase for when someone demonstrates the opposing point by trying to demonstrate their point? [duplicate]

Question

I think there is a re-occurring situation where someone uses some example of something as a strong argument for a position they have. Yet, ironically, you may feel the example they chose actually perfectly demonstrates the opposing position to theirs.

For example, if some people complained that something, X, is offensive, and then said that you would think so too if it were directed at you. So then, to prove that point, someone does that offensive thing, directed at you. Except, you think it’s a perfect case in point of it not being offensive; now you can say so more firmly because even when it was directed at you you didn’t find it offensive or wrong.

I wonder if there is a French term for this (in line with many great French terms in English like coup de grace, faux pas, etc.), or a Latin term from rhetoric.

Answer 1

There is a frequently used term having that meaning; it applies in particular to plans but it can be extended to situations involving plan-like schemes: "to backfire".

(Cambridge Dictionary) backfire (of a plan) to have the opposite result from the one you intended:

(OALD) backfire verb ​[intransitive] to have the opposite effect to the one intended, with bad or dangerous

(Backfired Magic: A Reverse Harem Paranormal Romance Steamy - Jade Alters · 2019) I did a stupid love spell, and it royally backfired. I don't know. But the guy I thought it would attract treated me like absolute dirt today.

(The Nation - Volume 178 - 1954 ) But one thing is clear : the hearings have backfired . Nearly everyone involved has suffered some damage , the temporary subcommittee perhaps even more than the parties themselves.

(Miscellaneous Publications: Including Issues of Fair Comment Fair Campaign Practices Committee · 1959)

• At least 16 clearly backfired , helping the candidate they were intended to harm
• Smears against Eisenhower were numerous and backfired decisively.

(Inner Views: Filmmakers In Conversation - David Breskin · 1997) But it kind of backfired , because- Backfired ? How ? Because in some ways the white Southerners , who forced Christianity down the slaves ' throats , didn't realize that the personal empowerment Christianity gave the slaves led to a ...

(America: A Catholic Review of the Week - 1959) In fact, 55 per cent of the 1958 smears backfired, i.e., they helped elect the smeared candidate

(The Bulletin - 1989 ) But the NPA's ruthless efforts to enforce loyalty appear to have backfired . By all indications , most of the victims were not informers but loyal cadres , tortured and murdered in an epidemic of paranoia

Answer 2

Sounds like that person would be playing into someone's hands.

idiom : to do something that one does not realize will hurt oneself and help someone else

You're only playing into your accusers' hands by making accusations in return.

As in,

This complex argument incorporated nearly all the rationales used in previous attempts to prove Syrian whiteness. There was first the three-part equation that Syrians were Semites, hence Caucasian and therefore white. This had worked in cases where the judge had relied heavily on ethnology, but it was useless in front of judges like Smith who relied on the rationale of congressional intent. The second important component of the Syrian argument was the cultural one, the insistence that their " history and position "made them eligible for the privilege of citizenship. The third part of the argument turned on legal precedent, namely, that European Jews (who were also Semites) had been naturalized, and that the same should hold for Syrians. This argument, however, played into the hands of Judge Smith whose definition of white always turned on the question of European descent. In his opinion, a European Jew was first and foremost a European, "racially, physiologically, and psychologically a part of the peoples he lives among." A far more interesting argument would have been that Arabic-speaking Levantine Jews had already been naturalized, but for reasons that are unclear, neither the Syrians nor their lawyers chose this strategy. (Journal of American Ethnic History , 2001, Gualtieri, Sarah)

Answer 3

'Backfire' certainly provides the overall idea. What about 'an ironic turn of events' or 'ironic twist'?

backfire verb [I] (BAD RESULT).

(of a plan) to have the opposite result from the one you intended:

Her plans to make him jealous backfired on her when he started dating her best friend.