deduction
(dɪˈdʌkʃən)
Also 5 deduxion, 5–6 deduccion, 6 deduccoun.
[In some senses a. F. déduction (Oresme 14th c.), but in most ad. L. dēductiōn-em, n. of action from L. dēdūcĕre: see deduct, deduce.]
The action of deducting.
1. a. The action of deducting or taking away from a sum or amount; subtraction, abatement.
| 1483 in Arnolde Chron. (1811) 110 The sayde Ri. shall be chargeable for the hoole somme..wythot ony deduxion. 1496–7 Act 12 Hen. VII, c. 12 §4 Any deduccion or abatement befortyme allowed. 1646 Sir T. Browne Pseud. Ep. iv. xii. 217 He dyed in the day of his nativity, and without deduction justly accomplished the year of eighty one. 1776 Smith W.N. i. viii. (1869) I. 68 His rent..makes the first deduction from the produce of the labour which is employed upon land. 1827 Jarman Powell's Devises II. 55 The interest given to them was exclusive of, and with a deduction of, that sum. 1868 Freeman Norm. Conq. (1876) II. vii. 33 Charges of this kind must always be taken with certain deductions. |
b. That which is deducted or subtracted.
| 1546 in Eng. Gilds (1870) 197 Wyth the yerely Resolutes and deduccions goyng out of the same. 1557 Recorde Whetst. X j, For subtraction your nombers are sette downe after the common maner, firste the totall, and then the deduction. 1703 T. N. City & C. Purchaser 55 In taking out the Deductions for the Doors and Windows. |
2. a. A leading forth or away (spec. of a colony); conduct. Now rare or Obs.
| 1615 Chapman Odyss. vi. 455 Take such way, That you yourself may compass..Your quick deduction by my father's grace. 1677 Hale Prim. Orig. Man. ii. x. 228 Deductions of Colonies, and new Plantations. 1832 Blackw. Mag. XXXI. 574 The solemn deduction (to use the technical term) of a legitimate Roman colony. |
† b. fig. A leading up to something, introduction. Obs. rare.
| 1513 More Rich. III, Wks. 61 (R.) He sodainly lefte the matter, with which he was in hand, and without any deduction thereunto..began to repete those wordes again. |
† 3. The action or result of tracing out or setting forth in order; a detailed narration or account. Obs. (Cf. deduce 4, deduct v. 5.)
| a 1532 Remedie of Love (R.), Ordinately behoveth thee first to procede In deduction thereof [this werke]. 1603 Florio Montaigne i. ix. (1632) 17 A long counterfet deduction of this storie. 1670 Evelyn Mem. (1857) III. 222 A solemn deduction and true state of all affairs and particulars. 1748 Chesterfield Lett. II. clix. 71 It..gives a clear deduction of the affairs of Europe from the treaty of Munster to this time. 1826 C. Butler Life Grotius 34 We have thus brought down our historical deduction of the German Empire to the accession of the Emperor Charles. |
† 4. Mus. The succession of notes forming a hexachord: the singing of these in order. Obs.
| 1597 Morley Introd. Mus. 7 Now for the last tryall of your singing in continuall deduction sing this perfectly. 1609 Douland Ornith. Microl. 26 There are..three Deductions of this kinde. 1876 Stainer & Barrett Dict. Mus. Terms. |
† 5. a. The process of deducing or deriving from some source; derivation. Obs.
| 1612 Drayton Poly-olb. ix. Notes 145 Affirming that our Britons from them..had deduction of this nationall title. 1669 Gale Crt. Gentiles i. i. ii. 12 The deduction of the Greek Leters from the Hebrew. 1755 Johnson Dict., Grammar Eng. Tongue, Etymology teaches the deduction of one word from another. |
b. concr. That which is derived. rare.
| a 1835 Rickman Archit. 30 There may be some doubt, whether the modern Ionic capital is not rather a deduction from the Composite than the contrary. |
6. a. The process of deducing or drawing a conclusion from a principle already known or assumed; spec. in Logic, inference by reasoning from generals to particulars; opposed to induction.
| 1594 Hooker Eccl. Pol. i. xiv. (1611) 42 And show the deduction thereof out of Scripture to be necessarie. 1651 Hobbes Govt. & Soc. iii. §26 The deduction of these Lawes is so hard, that [etc.]. 1736 Butler Anal. ii. vi. 308 A matter of deduction and inference. 1789 Belsham Ess. I. i. 4 It follows by easy and irrefragable deduction. 1860 Abp. Thomson Laws Th. §113 Deduction the process of deriving facts from laws, and effects from their causes. a 1862 Buckle Civiliz. (1869) III. v. 291 By deduction we descend from the abstract to the concrete. |
b. transf. That which is deduced; an inference, conclusion.
| 1532 More Confut. Tindale Wks. 461/2 Yet if he would..neither vse false deduccions of hys owne, nor refuse our deduccions yf we deduce them wel. 1671 J. Webster Metallogr. i. 9 From all this we shall only draw these Deductions. 1736 Butler Anal. i. ii. 35 It is not so much a Deduction of Reason, as a Matter of Experience. 1876 Freeman Norm. Conq. V. xxii. 21 The whole evidence..bears out the general deductions which I have made. |
† 7. Reduction. Obs. rare. (Cf. deduct 7.)
| 1650 Bulwer Anthropomet. 172 The Deduction and Moderation of their Excrescencie. |
8. attrib., deduction theorem Logic, the rule or metatheorem that if within a system a formula B is derivable from a formula A, then ‘If A then B’ is a theorem of the system; the principle of conditionalization.
| 1941 O. Helmer tr. Tarski's Introd. Logic vi. 127 A general law..which..is known as the law of deduction (or the deduction theorem). 1951 Mind LX. 382 The Deduction Theorem holds for the calculus of causal propositions. 1962 W. & M. Kneale Devel. Logic v. 320 The principle of conditionalization (or ‘deduction theorem’)..was taken for granted by Aristotle. |