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
3. (Anat.) The exhibition and
explanation of a dissection or other anatomical
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
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