SYLLOGISM

syllogism

(noun) deductive reasoning in which a conclusion is derived from two premises

Source: WordNet® 3.1

Etymology

Noun

syllogism (plural syllogisms)

(logic) An argument whose conclusion is supported by two premises, of which one contains the term that is the predicate of the conclusion, and the other contains the term that is the subject of the conclusion; common to both premises is a term that is excluded from the conclusion.

Meronyms: major premise, minor premise

(obsolete) A trick, artifice; an extremely subtle, sophisticated, or deceptive argument; a sophism.

Source: Wiktionary

Syl"lo*gism, n. Etym: [OE. silogisme, OF. silogime, sillogisme, F. syllogisme, L. syllogismus, Gr. syllogismo`s a reckoning all together, a reasoning, syllogism, fr. syllogi`zesqai to reckon all together, to bring at once before the mind, to infer, conclude; sy`n with, together + logi`zesqai to reckon, to conclude by reasoning. See Syn-, and Logistic, Logic.] (Logic)

Definition: The regular logical form of every argument, consisting of three propositions, of which the first two are called the premises, and the last, the conclusion. The conclusion necessarily follows from the premises; so that, if these are true, the conclusion must be true, and the argument amounts to demonstration;

Note: as in the following example: Every virtue is laudable; Kindness is a virtue; Therefore kindness is laudable. These propositions are denominated respectively the major premise, the minor premise, and the conclusion.

Note: If the premises are not true and the syllogism is regular, the reasoning is valid, and the conclusion, whether true or false, is correctly derived.

Source: Webster’s Unabridged Dictionary 1913 Edition