Definitions
from The American Heritage® Dictionary of the English Language, 5th Edition.
- noun Disproof of a proposition by showing that it leads to absurd or untenable conclusions.
from The Century Dictionary.
- noun A reduction to an absurdity; the proof of a proposition by proving tho falsity of its contradictory opposite: an indirect demonstration.
from Wiktionary, Creative Commons Attribution/Share-Alike License.
- noun mathematics, logic The method of proving a statement by assuming the statement is false and, with that assumption, arriving at a blatant
contradiction .
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- noun (reduction to the absurd) a disproof by showing that the consequences of the proposition are absurd; or a proof of a proposition by showing that its negation leads to a contradiction
Etymologies
from The American Heritage® Dictionary of the English Language, 4th Edition
[Medieval Latin reductiō ad absurdum : Latin reductiō, a bringing back, reduction + Latin ad, to + Latin absurdum, absurdity, from neuter of absurdus, absurd.]
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Examples
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In addition, it does so through reasoning alone, with tools such as “reductio ad absurdum” – a mode of argumentation that seeks to prove a claim by deriving an absurdity from its denial.
How metaphysics probes hidden assumptions to make sense of reality Daniel Cossins 2025
mcgelligot commented on the word reductio ad absurdum
Reductio ad absurdum is proving something must be true because its negative is impossible.
November 14, 2008