Dem`on*stra"tion (?), n. [L. demonstratio: cf. F. d'emonstration.]


The act of demonstrating; an exhibition; proof; especially, proof beyond the possibility of doubt; indubitable evidence, to the senses or reason.

Those intervening ideas which serve to show the agreement of any two others are called "proofs;" and where agreement or disagreement is by this means plainly and clearly perceived, it is called demonstration. Locke.


An expression, as of the feelings, by outward signs; a manifestation; a show.

Did your letters pierce the queen to any demonstration of grief? Shak.

Loyal demonstrations toward the prince. Prescott.

3. Anat.

The exhibition and explanation of a dissection or other anatomical preparation.


(Mil.) a decisive exhibition of force, or a movement indicating an attack.

5. Logic

The act of proving by the syllogistic process, or the proof itself.

6. Math.

A course of reasoning showing that a certain result is a necessary consequence of assumed premises; -- these premises being definitions, axioms, and previously established propositions.

Direct, ∨ Positive, demonstration Logic & Math., one in which the correct conclusion is the immediate sequence of reasoning from axiomatic or established premises; -- opposed to Indirect, ∨ Negative, demonstration (called also reductio ad absurdum), in which the correct conclusion is an inference from the demonstration that any other hypothesis must be incorrect.


© Webster 1913.

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