Syllogism

Syllogism, the full logical from of a single argument. to a legitimate syllogism it is essential that there should be three, and no more than three, pro-positions-namely, the conclusion, or proposition to be proved, and two other propositions which together prove it, and which are called the premises. There must be three terms, viz., the subject and predicate of the conclusion, and another called the middle term, which must be found in both premises, since it is by means of it that the other two terms are to be connected together, e.g., all men are mortal; John is a man; therefore John is mortal. Consult Jevon's or Mill's or Bain's Logic.