Forms: 4–5 logik, 4–6 logyk(e, 4–7 logike, logique, 6 logycke, 6–7 logicke, 7–8 logick, 6– logic. [a. F. logique (13th c.), ad. med.L. logica, ad. Gr. λογική (first found in Cicero; ellipt. for ἡ λογικὴ τέχνη, rendered in med.L. by ars logica), fem. of λογικός (whence L. logicus) pertaining to reasoning, f. λόγος word, oration, reasoning, reason, etc.: see LOGOS. The word is current in all the mod. Rom. and Teut. langs.: Sp. lógica, Pg., It., Du. logica, Sw. logika, Ger., Da. logik.
Cicero uses also logica neut. pl. = Gr. τὰ λογικά ‘logics’ (see 1 b below).]
1. The branch of philosophy that treats of the forms of thinking in general, and more especially of inference and of scientific method. (Prof. J. Cook Wilson.)
The proper scope of this department of study has been and is much controverted, and books on ‘logic’ differ widely in the range of subjects which they include. The definition formerly most commonly accepted is ‘the art of reasoning’; for various modern definitions see the later quots. At all times the vulgar notion of ‘logic’ has been largely that it is a system of rules for convincing or confounding an opponent by argument.
In the Middle Ages logic (or DIALECTIC, q.v.) was one of the three sciences composing the ‘trivium,’ the former of the two divisions of the seven ‘liberal arts.’
1362. Langl., P. Pl., A. XI. 127. Lo, logyk I lered hire and al þe lawe after.
c. 1386. Chaucer, Prol., 286. A Clerk ther was of Oxenford also, That unto logik hadde longe ygo.
1387. Trevisa, Higden (Rolls), III. 251. Permenides satte ten ȝere on a roche, and byþouȝt hym of þe art of logik.
1390. Gower, Conf., III. 366. Sche made him such a Silogime, That he foryat al his logique.
1481. Caxton, Myrr., I. viii. 34. The seconde science is logyke…. This science proueth the pro and the contra.
1551. T. Wilson, Logike, A 1 b. Logike is an arte to reason probablie.
1593. Nashe, Christ’s T., 49 b. Law, Logique, and the Swizers, may be hir’d to fight for any body.
1605. Bacon, Adv. Learn., II. xviii. § 5 (1891), 179. Logic differeth from rhetoric … in this, that logic handleth reason exact and in truth, and rhetoric handleth it as it is planted in popular opinions and manners.
1707. Floyer, Physic. Pulse-Watch, 12. Galen brings too much Logick into his Treatise of Pulses, and mentions the Predicaments [etc.].
1776. Adam Smith, W. N., V. i. (1869), II. 354. Logic, or the science of the general principles of good and bad reasoning.
1837. Sir W. Hamilton, Logic, i. (1866), I. 4. Logic is the Science of the Laws of Thought as Thought.
1843. Mill, Logic, Introd. (1846), 9. Logic is not the science of Belief, but the science of Proof, or Evidence.
1870. Jevons, Elem. Logic, i. 1. Logic may be most briefly defined as the Science of Reasoning.
b. pl. in the same sense. (Cf. ethics, etc.) Not now in general use.
1637. Gillespie, Eng.-Pop. Cerem., III. vii. 120. I remember, that I heard in the logicks, of pars essentialis or Physica.
1651. J. Jane, Εικων Ακλαστος, 247–8. The Libellers Logickes serves him to as litle purpose, as his historie.
1698. Keill, Exam. Theory Earth (1734), 89. The Theorist in this part has endeavoured to give us a proof of his great skill in Logicks.
1862. Dublin Univ. Cal., 48. The following books have been appointed for the Examination for Logical and Ethical Moderatorships:—Logics. All the Logics of the Undergraduate Course.
¶ c. Used by translators and expounders of Hegel for: The fundamental science of thought and its categories (including metaphysics or ontology).
1838. Penny Cycl., XII. 99/2. Hegel divides philosophy into three parts—1. Logic, or the science of the idea in and by itself.
1854. A. Tulk, trans. Chalybäus’ Speculat. Philos., 313. The whole of philosophy … has three cardinal divisions,—the Logic, which with Hegel, as is readily seen, implies also Metaphysics; the Philosophy of Nature; and Philosophy of Mind.
1874. W. Wallace, Logic of Hegel, i. § 9. Speculative Logic contains all previous Logic and Metaphysics.
1890. W. S. Hough, trans. Erdmann’s Hist. Phil., II. 686. The fundamental science, which Hegel calls Logic, but remarks at the same time that it may equally well be called Metaphysics or Ontology.
2. A system or a particular exposition of logic; a treatise on logic. Also, the science or art of reasoning as applied to some particular department of knowledge or investigation.
1377. Langl., P. Pl., B. XII. 267. To lowe lybbyng men þe larke is resembled; Arestotle þe grete clerke suche tales he telleth; Thus he lykneth in his logyk þe leste foule oute.
1594. R. Ashley, trans. Loys le Roy, 125 b. They which write for the most part, do nothing but … heape one on another Grammars, Rhetoricks, Logicks, Institutions [etc.].
1699. Bentley, Phal., xi. 296. If Mr. B. had studied his new Logic more and his Phalaris less; he had made better work in the way of Reasoning.
1756. Burke, Subl. & B., Introd., Wks. I. 96. The logick of taste, if I may be allowed the expression.
1833. Sir W. Hamilton, Discuss. (1853), 165. The arbitrary laws of our present logics. Ibid. (1838), Logic, App. (1866), II. 244. The Italian and Latin Logics of Genovesi are worthy of your attention.
1880. W. Wallace, in Encycl. Brit., XI. 619/2. The logic of Hegel is the only rival to the logic of Aristotle…. His logic is an enumeration of the forms or categories by which our experience exists.
1882. R. Adamson, ibid., XIV. 782/1. The metaphysical logic of Hegel, the empirical logic of Mill, the formal logic of Kant.
1884. R. Adamson, in Mind, Jan., 123. In that speculative domain [Germany], Logics swarm as bees in spring-time.
3. Logical argumentation; a mode of argumentation viewed as good or bad according to its conformity or want of conformity to logical principles. To chop logic: see CHOP v.2 8. Also, logical pertinence or propriety.
1601. Bp. W. Barlow, Serm. Paules Crosse, Pref. 2. Malice marres logike and charitie both.
1646. Sir T. Browne, Pseud. Ep., I. iv. 15. This was the Logick of the Jews, when they accused our Saviour unto Pilate.
1647. Clarendon, Hist. Reb., I. § 150. But when they … instead of giving were required to pay, and by a logic that left no man any thing which he might call his own.
1738. Johnson, London, 71. [I] A statesman’s logick unconvinced can hear.
1795. Gentl. Mag., 541/1. You will be astonished at the logick which could draw such an inference from that address.
1830. Macaulay, Rob. Montgomery, Ess. (1887), 140. We should be sorry to stake our faith in a higher Power on Mr. Robert Montgomery’s logic.
1843. Carlyle, Past & Pr., III. v. Driven alike by its Logic, and its Unlogic.
1850. Mrs. Browning, Poems, I. 4. Gab. Depart. Luc. And where’s the logic of ‘depart?’
1863. E. V. Neale, Anal. Th. & Nat., 33. As … Sir William Hamilton argues with overpowering learning and logic.
1891. Daily News, 23 March, 4/7. England, as Mr. Disraeli on[c]e said, is not governed by logic.
b. transf. A means of convincing or proving.
1682. G. Topham, Rome’s Tradit., Ep. Ded. Bonner’s Logick, Fire and Faggot.
1711. Addison, Spect., No. 239, ¶ 8. A certain Grand Monarch … writ upon his Great Guns—Ratio ultima Regum, The Logick of Kings.
1816. Sporting Mag., XLVIII. 180. On setting to Lancaster cleanly hit Ford down; when it was loudly vociferated ‘What do you think of that for logic?’
1859. E. FitzGerald, trans. Omar, xliii. (1899), 83. The Grape that can with Logic absolute The Two-and-Seventy jarring Sects confute.
1869. J. Eadie, Comm. Galatians, 132. The logic of their facts was irresistible, for they could not be gainsaid.
1880. Daily Tel., 28 Oct., 5/1. Nevertheless, with the best will in the world to give up the southern gateway to the Indian plains, the ‘logic of events’ may prove too strong for them, and what reason could not effect necessity may enforce.
1901. Scotsman, 14 March, 7/5. Their territory … was annexed to the British domain in consequence of the terrible logic of war.
4. attrib. = of or pertaining to logic.
In some of the earlier quots. possibly a real adj. (like L. logicus, F. logique) = LOGICAL 1.
1581. J. Hamilton, Catholik & Facile Traictise, 19. Zung men neu cum out of the grammer or logic scholes.
1608. T. Morton, Preamble Encounter, 107. I haue now my Mitigator vpon a Logicke racke.
1613. Jackson, Creed, II. ii. § 6. Most of them vsually penned in a base and barbarous Logicke phrase.
1628. T. Spencer, Logick, 36. This distinction, is received in all the Logick schooles.
1635. Pagitt, Christianogr., II. vii. (1636), 79. Endeavoring to enthrall us with sophisticall arguments and Logick quirks.
1652. Collinges, Caveat for Prof. (1653), A iij b. They would not endure to stand in a Logick forme.
1678. Gale, Crt. Gentiles, III. 8. Sin is not a mere nothing, but has some kind of logic positivitie or notional entitie.
1734. R. Wodrow, Life J. Wodrow (1828), 18. I had a copy of Logick and Ethick Dictates in my father’s hand among his school books.
1742. Young, Nt. Th., IX. 865. Wouldst thou on metaphysic pinions soar? Or wound thy patience amid logic thorns?
1843. Carlyle, Past & Pr., III. v. 223. Questions insoluble, or hitherto unsolved; deeper than any of our Logic-plummets hitherto will sound.
1869. Browning, Ring & Bk., VIII. 243. He’ll keep clear of my cast, my logic-throw.
5. Comb.: † logic-fisted a., having the hand clenched, like Logic in personification (see Cic., Orat., xxxii. 113; Bacon, Adv. Learn., II. xviii. § 5).
1683. Kennett, trans. Erasm. on Folly, 80. One, with an open-handed freedome, spends all he lays his fingers on; another with a Logick-fisted gripingness, catches at, and grasps all he can come within the reach of.
