Part 153

2. To show, or make evident, by reasoning or proof; to prove by deduction; to establish so as to exclude the possibility of doubt or denial.

We can not demonstrate these things so as to show that the contrary often involves a contradiction.

Tillotson.

3. (Anat.) To exhibit and explain (a dissection or other anatomical preparation).

Dem"on*stra`ter, n. See Demonstrator.

Dem`on*stra"tion (?), n. [L. demonstratio: cf. F. démonstration.] 1. 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.

2. 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.

4. (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, or Positive, demonstration (Logic & Math.), one in which the correct conclusion is the immediate sequence of reasoning from axiomatic or established premises; -- opposed to Indirect, or 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.

De*mon"stra*tive (?), a. [F. démonstratif, L. demonstrativus.] 1. Having the nature of demonstration; tending to demonstrate; making evident; exhibiting clearly or conclusively. "Demonstrative figures." Dryden.

An argument necessary and demonstrative.

Hooker.

2. Expressing, or apt to express, much; displaying feeling or sentiment; as, her nature was demonstrative.

3. Consisting of eulogy or of invective. "Demonstrative eloquence." Blair.

Demonstrative pronoun (Gram.), a pronoun distinctly designating that to which it refers.

De*mon"stra*tive, n. (Gram.) A demonstrative pronoun; as, "this" and "that" are demonstratives.

De*mon"stra*tive*ly (?), adv. In a manner fitted to demonstrate; clearly; convincingly; forcibly.

De*mon"stra*tive*ness, n. The state or quality of being demonstrative.

Dem"on*stra`tor (?; 277), n. [L.: cf. F. démonstrateur.] 1. One who demonstrates; one who proves anything with certainty, or establishes it by indubitable evidence.