deduce

From Late Middle English deducen (“to demonstrate, prove, show; to argue, infer; to bring, lead; to turn (something) to a use; to deduct”),^[1] borrowed from Latin dēdūcere, the present active infinitive of dēdūcō (“to lead or bring out or away; to accompany, conduct, escort; (figuratively) to derive, discover, deduce”); from dē- (prefix meaning ‘from, away from’) + dūcere (the present active infinitive of dūcō (“to conduct, guide, lead; to draw, pull; to consider, regard, think”), ultimately from Proto-Indo-European *dewk- (“to lead; to draw, pull”)).^[2]

• (Received Pronunciation) IPA^(key): /dɪˈdjuːs/, (UK non-RP also) /dɪˈdʒuːs/
• (General American) IPA^(key): /dɪˈdus/, /də-/, (rarely) /-ˈdjus/

• Audio (General American):

  (file)

• Rhymes: -uːs
• Hyphenation: de‧duce
• Homophone: dejuice (yod-coalescence)

deduce (third-person singular simple present deduces, present participle deducing, simple past and past participle deduced)

1. (transitive) To reach (a conclusion) by applying rules of logic or other forms of reasoning to given premises or known facts.

   Synonyms: conclude, infer

   Antonym: induce

   • 1593 September 11, [Robert Persons?], “The Second Parte of This Letter Conteyning Certaine Considerations of State vppon the Former Relation”, in [Henry Walpole], transl., Nevves from Spayne and Holland Conteyning an Information of Inglish Affayres in Spayne vvith a Conferrence Made theruppon in Amsterdame of Holland. , : , →OCLC, folio , recto and verso:

     he puritan buyldeth directly vpon the proteſtants firſt groundes in religion, & deduceth therof clearly and by ordinary conſequence al his concluſions, which the proteſtant cannot deny by divinity, but only by pollicy & humane ordination, or by turning to catholique anſwers contrary to ther owne principles: […]

   • 1605, Francis Bacon, “The Second Booke”, in The Twoo Bookes of Francis Bacon. Of the Proficience and Aduancement of Learning, Diuine and Humane, London: [Thomas Purfoot and Thomas Creede] for Henrie Tomes, , →OCLC, folio 110, verso:

     hoſe principles or firſt poſitions, have no diſcordance with that reaſon, which draweth downe and diduceth the inferiour poſitions.

   • 1650, Thomas Browne, “Of the Great Climactericall Year, that is, Sixty Three”, in Pseudodoxia Epidemica: , 2nd edition, London: A Miller, for Edw Dod and Nath Ekins, , →OCLC, 4th book, page 187:

     Laſtly, One way more there may be of miſtake, at that not unuſuall among us, grounded upon a double compute of the year; the one beginning from the 25 of March, the other from the day of our birth unto the ſame again, which is the naturall account. Now hereupon many men frequently miſcaſt their daies; for in their age they diduce the account not from the day of their birth, but the year of our Lord, wherein they were born.

   • 1651, Thomas Hobbes, “Of Counsell”, in Leviathan, or The Matter, Forme, & Power of a Common-wealth Ecclesiasticall and Civill, London: for Andrew Crooke, , →OCLC, 2nd part (Of Common-wealth), page 132:

     Counsell, is where a man ſaith, Doe, or Doe not this, and deduceth his reaſons from the benefit that arriveth by it to him to whom he ſaith it. And from this it is evident, that he that giveth Counſell, pretendeth onely (whatſoever he intendeth) the good of him, to whom he giveth it.

   • 1685 April 24, Wallis, “A Discourse Concerning the Air’s Gravity, Observd in the Baroscope, Occasioned by that of Dr. Garden; ”, in Philosophical Transactions: Giving Some Accompt of the Present Undertakings, Studies and Labours of the Ingenious in Many Considerable Parts of the World, volume XV, number 171, Oxford, Oxfordshire: Sam Smith  ; and Hen Clements , published 20 May 1685 [Julian calendar; 30 May 1685], →DOI, →OCLC, page 1007:

     From the comparative weight or lightneſs of the Air at different times, he deduceth alſo the riſing and falling of Vapours in it.

   • 1689 (indicated as 1690), [John Locke], “No Innate Principles in the Mind”, in An Essay Concerning Humane Understanding. , London: Eliz Holt, for Thomas Basset, , →OCLC, book I, § 9, page 6:

     But how then can thoſe Men think the uſe of Reaſon neceſſary to diſcover Principles that are ſupposed innate, when Reaſon (if we may believe them) is nothing elſe, but the Faculty of deducing unknown Truths from Principles or Propoſitions, that are already known?

   • 1756, “An Abstract of the Reciprocal Duties of Representatives and Their Constituents, on Constitutional Principles”, in A New System of Patriot Policy. Containing the Genuine Recantation of the British Cicero. , London: Jacob Robinson, , →OCLC, section IV, page 39:

     Now Principles, when deduced by Diſcourſe of ſound Reaſon, may, from the Content of Mankind, take the Name and Force of a Law; but the Faculty which deduceth thoſe Principles, cannot with the leaſt Propriety be deemed a Law. This is confounding Cauſes with Effects, and attributing the Property to the Faculty creating, which only belongs to the Subject created.

   • 1831 October 31, Mary W Shelley, “Letter IV. To Mrs. Saville, England.”, in Frankenstein: Or, The Modern Prometheus (Standard Novels; IX), 3rd edition, London: Henry Colburn and Richard Bentley, , →OCLC, page 17:

     I do not know that the relation of my disasters will be useful to you; yet, when I reflect that you are pursuing the same course, exposing yourself to the same dangers which have rendered me what I am, I imagine that you may deduce an apt moral from my tale; one that may direct you if you succeed in your undertaking, and console you in case of failure.

2. (transitive, uncommon) To examine, explain, or record (something) in an orderly manner.
   • 1625 (first performance), Ben Jonson, The Staple of Newes. , London: I B for Robert Allot , published 1631, →OCLC, Act II, scene ii, page 23:

     Pye[d-mantle]. […] Sir, I haue drawne / A Pedigree for her Grace, though yet a Nouice / In that ſo noble ſtudy. […] I haue deduc'd her.— […]

   • 1635 June 15 (Gregorian calendar), James Howell, “XXIX. To the Right Honourable Sir Peter Wichts, Lord Ambassador at Constantinople.”, in Epistolæ Ho-Elianæ. Familiar Letters Domestic and Forren. , 3rd edition, volume I, London: Humphrey Mos[e]ley, , published 1655, →OCLC, section VI, pages 249–250:

     It ſeems there is ſome angry Star that hath hung over this Buſineſs of the Palatinate from the beginning of theſe German Wars to this very Day, which will too evidently appear, if one ſhould mark and deduce Matters from their firſt Riſe.

   • a. 1749 (date written), James Thomson, “Spring”, in The Seasons, London: A Millar, and sold by Thomas Cadell, , published 1768, →OCLC, page 23, lines 573–578:

     Lend me your ſong, ye nightingales! oh pour / The mazy-running ſoul of melody / Into my varied verſe! while I deduce, / From the firſt note the hollow cuckoo ſings, / The ſymphony of Spring, and touch a theme / Unknown to fame, the Paſſion of the groves.

   • 1776, Edward Gibbon, “Reign of Claudius.—Defeat of the Goths.—Victories, Triumph, and Death of Aurelian.”, in The History of the Decline and Fall of the Roman Empire, volume I, London: W Strahan; and T Cadell, , →OCLC, page 296:

     The general deſign of this work will not permit us minutely to relate the actions of every emperor after he aſcended the throne, much leſs deduce the various fortunes of his private life.

   • 1822, [Walter Scott], chapter I, in Peveril of the Peak. , volume II, Edinburgh: Archibald Constable and Co.; London: Hurst, Robinson, and Co., →OCLC, page 26:

     If you leave this Isle, and got to the court of England, see what regard there will be paid to the old pedigree that deduces your descent from kings and conquerors.

3. (transitive, archaic) To obtain (something) from some source; to derive.
   • c. 1699 – 1703, Alexander Pope, “The First Book of Statius His Thebais”, in The Works of Mr. Alexander Pope, volume I, London: W Bowyer, for Bernard Lintot, , published 1717, →OCLC, pages 303–304:

     O Goddeſs, ſay, ſhall I deduce my rhimes / From the dire nation in its early times, / Europa’s rape, Agenor’s ſtern decree, / And Cadmus ſearching round the ſpacious ſea?

   • 1821 July, A. Heraud [John Abraham Heraud?], “Apostrophe to the New River”, in Sylvanus Urban , editor, The Gentleman’s Magazine: And Historical Chronicle, volume XCI, part 2 (New Series, volume XIV), London: John Nichols and Son, ; and sold by John Harris and Son (successors to Mrs. Newbery), ; and by Perthes and Besser, , →OCLC, page 66, column 2:

     The Spring whence thou [Hugh Myddelton] deduced'st the ample stream, / The Poet's and Historian's theme, / Trenching thy mighty aqueduct a way, / 'Till as the humble plains, the aspiring hills obey.

   • 1888, Virgil, “Book VI”, in Oliver Crane, transl., Virgil’s Æneid, , New York, N.Y.: The Baker & Taylor Co., , →OCLC, page 123, lines 832–834:

     Do not, my children, O do not accustom yourselves to such warfares, / Nor on your country's vitals thus turn your invincible valor: / Sooner refrain thou, thou who deducest thy race from Olympus!

4. (intransitive, archaic) To be derived or obtained from some source.
   • 1766, William Blackstone, “Of Title by Purchase, and First by Escheat”, in Commentaries on the Laws of England, book II (Of the Rights of Things), Oxford, Oxfordshire: Clarendon Press, →OCLC, page 256:

     y the ſtatute 7 Ann. c. 21 […] it is enacted, that, after the death of the pretender, and his ſons, no attainder for treaſon ſhall extend to the diſinheriting any heir, nor the prejudice of any perſon, other than the offender himſelf: which proviſions have indeed carried the remedy farther, than was required by the hardſhip above complained of; which is only the future obſtruction of deſcents, where the pedigree happens to be deduced through the blood of an attainted anceſtor.

5. (transitive, obsolete) To take away (something); to deduct, to subtract (something).

   to deduce a part from the whole

   • 1632 (first performance), Benjamin Jonson [i.e., Ben Jonson], “The Magnetick Lady: Or, Humors Reconcil’d. A Comedy ”, in The Workes of Benjamin Jonson. The Second Volume.  (Second Folio), London: Richard Meighen, published 1640, →OCLC, Act II, scene vi, page 26:

     Pra[ctise]. […] Well, Sir, the Contract / Is with this Gentleman, ten thouſand pound. […] Int[erest]. And what I have furniſh'd him with all o' the by, / To appeare, or ſo: A matter of foure hundred, / To be deduc'd upo' the payment—.

6. (transitive, obsolete, based on the word’s Latin etymon) To lead (something) forth.
   • 1612, [John Selden], “The Third Song. Illustrations.”, in Michael Drayton, edited by , Poly-Olbion. Or A Chorographicall Description of Tracts, Riuers, Mountaines, Forests, and Other Parts of this Renowned Isle of Great Britaine, , London: for M Lownes; I Browne; I Helme; I Busbie, →OCLC, page 51:

     Richard of the Vies will that Penda, K of Mereland, firſt deduced a colony of Cambridge men hither and cals it Crekelade, as other Kirklade with variety of names: […]

Regarding sense 1 (“to reach (a conclusion)”):

• For example, from the premises “all good people believe in the tooth fairy” and “Jimmy does not believe in the tooth fairy”, we deduce the conclusion “Jimmy is not a good person”. This particular form of deduction is called a syllogism.
• It is the nature of corollaries that they are usually deducible.

• diduce (obsolete)

• deductive reasoning on Wikipedia.Wikipedia

• deuced, educed

deduce

1. inflection of deducir:
   1. third-person singular present indicative
   2. second-person singular imperative

deduce

1. third-person singular present indicative of dedurre

dēdūce

1. second-person singular present active imperative of dēdūcō

Borrowed from Latin deducere, French déduire, with conjugation based on duce.

a deduce (third-person singular present deduce, past participle dedus) 3rd conjugation

1. (transitive) to infer, deduce (to conclude by reasoning or deduction, as from premises or evidence)

deduce

1. inflection of deducir:
   1. third-person singular present indicative
   2. second-person singular imperative