As a demonstration of logical fallacies, I often use this concept to establish the invalidity of common arguments that are poorly reasoned or justified by false assumptions.

reductio ad absurdum (re·duc·ti·o ad ab·sur·dum): / ri DUHK tee oh ad ab SUR duhm / (always italicized)
noun

(1) the carrying of something to absurd lengths; the application of a principle, rule, or argument so strictly or literally that it results in a ridiculous outcome
(2) a reduction to an absurdity
(3) disproof of a proposition or logical argument by showing that the ultimate conclusion or outcome is absurd (philosophy: logic)
(4) proof of a proposition or logical argument indirectly by showing that the contradictory argument results in absurdity (philosophy: logic)

[From Latin reductio ad absurdum meaning “reduction to the absurd.”]

Usage: Successful use of reductio ad absurdum is only possible when levied against those exhibiting flawed ratiocination borne of a failure to critically analyze their contentions and suppositions.