In-dūc'tion, n.

n. [Lat. inductio, Fr. induction, Pr. inductio, Sp. induccion, It. induzione. See INDUCT.]

1Sense 1. The act of inducting or bringing in; introduction; entrance; beginning; commencement.

I know not you; nor am I well pleased to make this time, as the affair now stands, the induction of your acquaintance. Beau. & Fl.

These promises are fair, the parties sure, And our induction full of prosperous hope. Shak.

2Sense 2. An introduction or introductory scene, as to a play, leading to the main action. [Obs.]

This is but an induction: I will draw The curtains of the tragedy hereafter. Massinger.

3Sense 3. (Philos.) The act or process of reasoning from a part to a whole, or from particulars to generals.

4Sense 4. (Eccl.) The introduction of a clergyman into a benefice, or giving possession of an ecclesiastical living; or the introduction of a person into an office by the usual forms and ceremonies.

5Sense 5. (Physics.) The property by which one body, having electrical, galvanic, or magnetic polarity, causes or induces it in another body without direct contact; an impress of molecular force or condition from one body on another without actual contact.

6Sense 6. (Math.) A process of demonstration in which a general truth is gathered from an examination of particular cases, the examination being so conducted that each case is made to depend on the preceding one;—called also successive induction. Math. Dict.

Electro-magnetic induction, the influence by which an electric or galvanic current produces magnetic polarity in certain bodies near or round which it passes.—Magneto-electric induction, the influence by which a magnet excites electric currents in closed circuits.

Logical induction (Philos.), an act or method of reasoning from all the parts discretively to the whole which they constitute, or into which they may be united collectively.—Philosophical induction, the inference or act of inferring that what has been observed or established in respect to a part, individual, or species, may, on the ground of analogy, be affirmed or received of the whole to which they belong.

This last is the inductive method of Bacon. It ascends from the parts to the whole, and forms, from the general analogy of nature, or special presumptions in the case, conclusions which have greater or less degrees of force, and which may be strengthened or weakened by subsequent experience. It relates to actual existences, as in physical science, or the concerns of life. Logical induction is founded on the necessary laws of thought; philosophical induction, on the interpretation of the indications or analogy of nature.

Synonyms—Deduction.—INDUCTION, DEDUCTION. In induction we observe a sufficient number of individual facts, and, on the ground of analogy, extend what is true of them to others of the same class, thus arriving at general principles or laws. This is the kind of reasoning in physical science. In deduction we begin with a general truth, and seek to connect it with some particular case by means of a middle term, or class of objects, known to be equally connected with both. Thus we bring down the general into the particular, affirming of the latter the distinctive qualities of the former. This is the syllogistic method. By induction Franklin established the identity of lightning and electricity; by deduction he inferred that dwellings might be protected by lightning-rods.