Forms: 4 silogime, 4–6 silogisme, 5–6 sylogysme, 5–7 sillogisme, 6 silogysme, sellogisme, 6–7 syllogisme, sylogisme, 7 sillogism, 7– syllogism. Also 6 in Lat. form syllogismus (sill-, sil-). [a. OF. silogime, later sil(l)ogisme, F. syllogisme (= It. sillo-, silogismo, Sp. silogismo, Pg. syllogismo), or ad. L. syllogismus, a. Gr. συλλογισμός , f. συλλογίζεσθαι το SYLLOGIZE.]
1. Logic. An argument expressed or claimed to be expressible in the form of two propositions called the premisses, containing a common or middle term, with a third proposition called the conclusion, resulting necessarily from the other two. Example: Omne animal est substantia, omnis homo est animal, ergo omnis homo est substantia.
The kind of syllogism illustrated by the above example is called simple or categorical. In valid categorical syllogisms, the premisses have the major and minor terms so disposed in respect of the position of the middle (see FIGURE sb. 23) and the quality and quantity of the premisses (see MOOD sb.2 1) that the conclusion affirms or denies the major term of the minor.
For hypothetical (also called complex), conjunctive, connexive, disjunctive syllogism, see these words. Demonstrative syllogism: one in which the premisses are true and necessary. † Horned syllogism (see HORNED 1 b): the dilemma.
1398. Trevisa, Barth. De P. R., XIX. cxxvi. (1495), mm b/2. Without nombre is not … Subiectum knowe fro the Predicatum: nother the conclusyon in Silogismes [orig. in sillogisticis] is distyngued fro the premysses.
c. 1430. Pilgr. Lyf Manhode, I. xix. (1869), 14. If ye wol eyther make jugementes, silogismes, other argumentes with oute me, shule ye neuere haue conclusioun.
c. 1480. Henryson, Mor. Fab., Prol. vii. Ane sillogisme propone and eik conclude.
1528. More, Dyaloge, I. Wks. 125/2. Well quod I and yet he commeth to hys perswasion by a sylogysme & reasonninge, almost as formall as is the argument, by whiche ye proue the kinde of man reasonable, wherof what other colleccion haue you that brought you first to perceiue it than that this man is resonable, and this man, & this man, and this man, and so forth all whom ye se.
1530. Tindale, Answ. More, I. xxvii. Wks. (1572), 288/1. I would fayne know in what figure that silogismus is made.
1532. More, Confut. Tindale, Wks. 504/1. This sillogisme is mine. And thys sillogisme yf Tindall would fayne wit in what figure it is made: he shal finde it in the first figure, and the third mode, sauing that ye mynor carieth his proofe wt him, which woulde elles in the same figure and the same mode haue made another sillogisme.
1542. Udall, Erasm. Apoph., 90 b, marg. A syllogisme, is a perfecte argumente or logike, in whiche, two thynges or moo, first putte, & the same graunted, the conclusion dooeth ineuitably foloe of necessitee.
c. 1590. Marlowe, Faustus, 140. I that haue with Consis sylogismes Graueld the Pastors of the Germane Church.
1633. G. Herbert, Temple, Ch. Mil., 55. Prayers chas’d syllogismes into their den, And Ergo was transform’d into Amen.
1646. Sir T. Browne, Pseud. Ep., VI. i. 275. Men do speak … in simple tearms and words, expressing the open notions of things, which the second act of reason compoundeth into propositions, and the last into syllogisms and forms of ratiocination.
1649. Evelyn, Liberty & Servitude, ii. Certaine it is, that our understanding cannot always impedite itselfe, that it should not acquiesce at the Conclusion of a demonstrative syllogisme, having before comprehended the first and second propositions.
1691. Norris, Pract. Disc., 143. The Sum of the whole may be reduced to this practical Syllogism. That which will bring a man peace at the last, is to be chiefly minded: But a Life of Piety and Vertue will bring a man Peace at the last. Therefore a Life of Piety and Vertue is to be chiefly minded.
1748. W. Duncan, Elem. Logic, III. i. (1752), 194. As every Act of Reasoning implies three several Judgments, so every Syllogism must include three distinct Propositions.
1781. Cowper, Conversat., 93. Though syllogisms hang not on my tongue, I am not surely always in the wrong!
1827. J. Huyshe, Logic, 85. A syllogism is an argument in which the terms are so placed with respect to each other, that the conclusion results necessarily from the premises, from the mere force of the expression, and without any consideration of the meaning of the terms themselves.
1830. Scott, Demonology, ix. 306. The pedantic sovereign considered the execution of every witch who was burnt as a necessary conclusion of his own royal syllogisms.
1833. Sir W. Hamilton, in Edin. Rev., LVII. 220. Hypothetical syllogisms, in the present acceptation, were first expounded, and the name first applied to them by Theophrastus and Eudemus.
1840. Macaulay, Ess. Clive (1843), III. 201. Here the House stopped. They had voted the major and minor of Burgoyne’s syllogism; but they shrank from drawing the logical conclusion.
1850. Kingsley, Alton Locke, xxxviii. The unconscious logic of association is often deeper and truer than any syllogism.
1892. J. Tait, Mind in Matter (ed. 3), 312. The ‘fool’ who said in his heart that ‘there was no God’ no doubt thought ho had wiped Him out by a syllogism.
b. transf. and allusively. An argument or something ironically or humorously regarded as such, esp. a specious or subtle argument or piece of reasoning; † in early use, a subtle or tricky speech; a poser; more widely, an artifice, trick.
1387. Trevisa, Higden (Rolls), VII. 371. He coude what hym nedede for to konne, outake fables and poetes, and wily and sly silogismes, þat he wolde nouȝt on caas vouchesauf forto lerne.
1390. Gower, Conf., III. 366. I syh there Aristotle also, Whom that the queene of Grece so Hath bridled, that in thilke time Sche made him such a Silogime, That he foryat al his logique.
c. 1400. Rom. Rose, 4457. Whanne she wole make A fulle good silogisme, I dreede That aftirward ther shal in deede Folwe an evelle conclusioun.
1402. Pol. Poems (Rolls), II. 63. Go grees a shoep undir the taile, that semeth the beter than with sotil sillogismes to parbrake thi witt.
1484. Caxton, Fables of Æsop, V. xiv. Thow hast not yet wel studyed, and knowest not yet the Sylogysmes.
1591. Greene, Farew. Folly, Wks. (Grosart), IX. 251. Measure not the length of an other mans foot by your owne shoe, but ioine the souldier and scholler in one sillogisme, and then the premises equall, conclude how you list.
1860. Motley, Netherl., I. viii. 501. An absolute sovereign, even without resorting to Philip’s syllogisms of axe and faggot, was apt in the sixteenth century to have the best of an argument with private individuals.
1879. Farrar, St. Paul, I. 225. They took refuge in what St. Chrysostom calls ‘the syllogism of violence.’
2. In generalized sense: The form of such arguments, or argumentation in that form; the form or instrument of reasoning from generals to particulars. Also, as a mental act: mediate inference or deduction (as distinguished from immediate inference and induction).
1588. Fraunce, Lawiers Logike, I. ii. 7. Questions … to be concluded by syllogisme, the onely iudge of all coherence or consequence.
1603. Holland, Plutarch’s Mor., 1356. Of the present dependeth all Syllogisme and reasoning, and that by the vertue & efficacie of a conjunction: for that if this thing be, such a thing went before: and conversim, if this be; that shall be.
1605. Bacon, Adv. Learn., II. xiii. § 4. 50 b. Certaine it is, that Middle Propositions, cannot be diduced from them [sc. some axioms] in Subiect of Nature by Syllogisme, that is, by Touch and Reduction of them to Principles in a Middle Terme. Ibid., II. xiv. § 12. 57 b. There beeing but foure kindes of demonstrations, that is by the immediate consent of the Minde or Sence; by Induction; by Syllogisme; and by Congruitie.
1690. Locke, Hum. Und., IV. xvii. § 4. We reason best and clearest, when we only observe the connexion of the Proofs, without reducing it to any Rule of Syllogism. Ibid., § 6. A Man knows first, and then he is able to prove syllogistically. So that Syllogism comes after Knowledge, and then a Man has little or no need of it.
1704. Norris, Ideal World, II. Pref. 8. What is syllogism but only a more recollected and express way of reasoning, the putting together of all the parts of an argument, and nothing but those parts, and that in their due form and order?
1774. Reid, Aristotle’s Log., Wks. (1846), 712/1. In reasoning by syllogism from general principles, we descend to a conclusion virtually contained in them. The process of induction is more arduous, being an ascent from particular premises to a general conclusion.
1821. Aldrich’s Artis Logicæ Rudim. (ed. 2), 110. The office of syllogism is not the discovery, but the application of truth; it consists in the practical use of knowledge, rather than the primary acquisition of it.
1843. Mill, Logic, II. i. I. 223. Reasoning, in the extended sense in which I use the term, and in which it is synonymous with Inference, is popularly said to be of two kinds: reasoning from particulars to generals, and reasoning from generals to particulars; the former being called Induction, the latter Ratiocination or Syllogism.
1867. Fowler, Deduct. Logic, III. iii. 80 (heading), On Mediate Inference or Syllogism.
1870. Jevons, Elem. Logic, xv. 127. Syllogism may thus be defined as the act of thought by which from two given propositions we proceed to a third proposition.
1877. E. Caird, Philos. Kant, I. 134. Syllogism is just the activity of thought whereby a judgment is made complete, as judgment is the activity of thought whereby a conception is made distinct.
