| 释义 |
logical, a. (and n.)|ˈlɒdʒɪkəl|
[f. logic n. and L. logic-us logic a. + -al1. Cf. med.L. logicālis and obs. F. (16th c.) logical.]
1. a. Of or pertaining to logic; also, of the nature of formal argument.
1500–20Dunbar Poems lxv. 9 The curious probatioun logicall. 1588Fraunce Lawiers Log. Ded., Since first I began to be a medler with these Logical meditations. 1626Bacon Sylva §98 But they are put off by the Names of Vertues, and Natures, and Actions, and Passions, and such other Logicall Words. 1646J. Hall Horæ Vac. 39 A Sermon, in which there would be Ethicall Truth as well as Logicall. 1651Baxter Inf. Bapt. 212, I beg'd..that we might keep close to the strictest Logicall Disputing. 1707Floyer Physic. Pulse-Watch 13 Galen then blam'd the School of Moses and Christ for want of Logical Demonstrations in their Discourses of Laws. 1844Whately Logic iii. Introd. (ed. 8) 156 Many Logical writers..have undertaken to give rules ‘for attaining clear ideas’. 1847J. D. Morell Hist. View Philos. (ed. 2) I. i. 95 To Logic, Hobbes devoted a considerable share of attention. The peculiarity of his logical system lies in the theory, that reasoning is merely a numerical calculation. 1851–5G. Brimley Ess., Tennyson 38 Our common speech, abounding in logical generalizations and names of classes. 1905B. Russell in Mind XIV. 490 The distinction of primary and secondary occurrences also enables us to deal with..the logical status of denoting phrases that denote nothing. 1922E. P. Adams tr. Einstein's Meaning of Relativity i. 1 The object of all science, whether natural science or psychology, is to co-ordinate our experiences and to bring them into a logical system. 1939Mind XLVIII. 304 To say that a term is of such and such a type or category is to say something about its ‘logical behaviour’, namely, about the entailments and compatibilities of the propositions into which it enters. 1966W. V. Quine Ways of Paradox viii. 67 This condition is met by the usual logical languages, and presumably it can be met likewise by languages adequate to science in general.
b. Computers and Electronics. Of or pertaining to the logic (logic n. 4) of computers and similar equipment; designed to carry out processes on electrical or other signals analogous to the processes of reasoning, deduction, etc., employed in (formal) logic; logical element = logic element (logic n. 4 b); logical operation: see 7; logical shift, a displacement of the digits of a sequence by a specified number of positions in a way that is not equivalent to multiplication by an integral power of the base; esp. a cyclic shift, in which digits taken from one end reappear, in the same order, at the other end.
In some of the uses below logical can equally well be regarded as having the sense of logical a. 1.
1946Burks et al. (title) Preliminary discussion of the logical design of an electronic computing instrument. (Rep. submitted to U.S. Army Ordnance Dept., PB 96703.) 1946Goldstine & von Neumann Princ. Large Scale Computing Machines in J. von Neumann Coll. Works (1963) V. 23 The Memory Organ... In performing an operation (arithmetical or logical) it is usually necessary to store the quantities entering into it. 1950[see coincidence 7 b]. 1956IRE Trans. Electronic Computers V. 132/2 One of the important properties of a digital computer is that it may be assembled simply and easily from a few well-chosen functional circuits. Each of these circuits represents a logical element that is useful to the system or logic designer in planning a computer. 1958Gotlieb & Hume High-Speed Data Processing iii. 34 A concise and informative way of describing a computer is to draw its logical diagram which shows the paths and effects of the various signals through it. Logical diagrams are built up largely of gates. Ibid. v. 89 In a logical or cyclic shift the digits lost off one end of the number appear at the other end. 1962Newnes Conc. Encycl. Nucl. Energy 671/2 Such a system is sometimes referred to as a logical switching system because the output responses are related by fixed rules to the inputs from the measurement channels. 1964F. L. Westwater Electronic Computers iii. 49 The practical engineer must have the last word. Not infrequently, a design engineer will ask the logical designer to make alterations for various reasons. 1970O. Dopping Computers & Data Processing vii. 117 In the logical shift, all bits take part and zeroes are shifted in at one end. This kind of shift is suitable for handling non-arithmetic information. 1971J. H. Smith Digital Logic vii. 133 The reader using logical gating should analyse his specifications to eliminate the trivial and reduce the circuit as far as possible.
2. That is in accordance with the principles of logic; conformable to the laws of correct reasoning.
1588A. Fraunce Lawiers Logike f. 120, I haue, for examples sake, put downe a Logicall Analysis of the second Aegloge in Virgill. 1689Prior 1st Ep. Fleetwood Shephard 39 Then he, by sequence logical, Writes best, who never thinks at all. 1814D. Stewart Hum. Mind II. i. §1. 47 A process of logical reasoning has been often likened to a chain supporting a weight. 1828Mill in Westm. Rev. IX. 144 Those who maintain, that to perform the logical analysis of an argument, in the manner pointed out by the syllogism, is not the best means of discovering whether it contain a flaw. 1845Coleridge Method in Encycl. Metrop. I. 42 These cannot be introduced into a scientific treatise without destroying the symmetry of its parts by a suspension of the logical order. 1900R. J. Drummond Relat. Apostol. Teach. i. 25 He wants a logical explanation of the Christian faith. 1958G. J. Warnock Eng. Philos. since 1900 ix. 120 The narrowly logical, context-neglecting manner adopted by the practitioners of ‘logical analysis’.
3. That follows as a reasonable inference or natural consequence; that is in accordance with the ‘logic’ of events, of human character, etc.
1860Motley Netherl. (1868) I. i. 11 Having the sovereignty to dispose of, it seemed logical that the Estates might keep it, if so inclined. 1874Stubbs Const. Hist. I. i. 3 In France accordingly feudal government runs its logical career. 1883tr. Stepniak's Undergr. Russia 121 It may be called the sign of a lofty mind to which heroism is natural and logical.
4. Of persons: Capable of reasoning correctly.
1664Pepys Diary 18 Nov., I find he is a very logicall man and a good speaker. 1712Addison Spect. No. 291 ⁋3 Nor is it sufficient, that a Man who sets up for a Judge in Criticism, should have perused the Authors above mentioned, unless he has also a clear and Logical Head. 1805J. Leyden in Scott's Prose Wks. IV. Biographies II. (1870) 179 You logical lads of Europe will be very little disposed to admit the legitimacy of the conclusion.
Comb.1901Edin. Rev. Oct. 290 The strong and logical-minded Manning.
5. [nonce-uses, after Gr. λογικός.] Characterized by reason; rational, reasonable.
a1652J. Smith Sel. Disc. i. iii. (1821) p. xxiii, We may..be too apt to rest in a mere ‘logical life’, an expression of Simplicius, without any true participation of the divine life. 1768–74Tucker Lt. Nat. (1834) II. 466 The logical worship is rendered reasonable service in Rom. xii. 1.
†6. n. pl. The subjects which are studied in a course of instruction in logic. little logicals or small logicals: certain minor questions of the science of logic, which formed the subject of the Parva Logicalia, a collection of treatises by Petrus Hispanus and others. Obs. exc. Hist.
1551Robinson tr. More's Utop. ii. (1895) 185 Those rules of restryctyons, amplyfycatyons, and supposytyons very wittelye inuented in the small Logycalles, whyche heare oure chyldren in euerye place do learne. 1569J. Sandford tr. Arippa's Van. Artes 22 b, Other intollerable, and vaine wordes which are writen in the little Logicals. 1691Wood Ath. Oxon. I. 10 John Colet..after he had spent seven years in Logicals and Philosophicals, was licensed to proceed in Arts. 1716M. Davies Athen. Brit. II. 328 He was educated in Grammaticals in Wikeham-School..in Logicals and Philosophicals in New College Oxon.
7. Special collocations (see also sense 1 b): logical addition, the formation of a logical sum; logical atomism (see atomism 1 b); logical constant (see quots. 1903, 1914); logical construction, an entity theoretically superfluous in that any statement referring to it can be replaced by an equivalent statement making no reference to it; logical empiricism, the name given to philosophical theories which replaced those of logical positivism (see quots. 1936, 1937); so logical empiricist; logical fiction = logical construction; logical form, the form, as distinct from the content, of a proposition, argument, etc., which can be expressed in logical terms; logical grammar, the rules of word-use in a proposition upon which its logical, as opposed to its purely grammatical, sense or meaning is held to depend; so logical-grammatical adj.; logical implication, implication which is based on the formal and not the material relationship between propositions; logical machine, an apparatus designed to facilitate logical calculations; also transf.; logical multiplication, the formation of a logical product; logical operation, an operation of the kind dealt with in logic (such as conjunction or negation); any analogous (non-arithmetical) operation on numbers, esp. binary numbers, in which each digit of the result depends on only one digit in each operand; logical paradox (see quot. 1967); logical positivism, the name given to the theories and doctrines of philosophers active in Vienna in the early 1930s (the Vienna Circle), which were aimed at evolving in the language of philosophy formal methods for the verification of empirical questions similar to those of the mathematical sciences, and which therefore eliminated metaphysical and other more speculative questions as being logically ill-founded; hence logical positivist; logical product, the conjunction of two or more propositions, or the intersection of two or more sets (written p {logicand} q, p {intsec} q, p.q, pq, p and q); logical structure, the formal framework of logical rules to which a theory, language, proposition, etc., must conform in order to have truth-value; logical subject, the subject which is implied in a sentence or proposition, or which exists in the deep structure of a sentence; logical sum, the disjunction of two or more propositions, or the union of two or more sets (written p {logicor} q, p {union} q, p or q, p + q); logical syntax (see quot. 1934); logical truth, that which is true in logical or formal terms regardless of material meaning; logical word, a word of the type which gives logical context or form to a proposition but which, by itself, is non-representational and without meaning (see quot. 1940).
1868C. S. Peirce in Proc. Amer. Acad. Arts & Sci. VII. 250 Let a + b denote all the individuals contained under a and b together. The operation here performed will differ from arithmetical addition in two respects: 1st, that it has reference to identity, not to equality; and 2d, that what is common to a and b is not taken into account twice over... The process denoted by +..I shall call the process of logical addition. 1903B. Russell Princ. Math. ii. 18 From this point we can prove the laws of contradiction and excluded middle and double negation, and establish all the formal properties of logical multiplication and addition—the associative, commutative and distributive laws. 1970O. Dopping Computers & Data Processing i. 23 In Boolean algebra..instead of the usual mathematical operations, there are certain logical operations; the most common ones of these are logical addition, logical multiplication, and negation.
1914, etc. Logical atomism [see atomism 1 b]. 1973E. Gellner in Horton & Finnegan Modes of Thought 179 The..formal fact of the existence and nature of the mosaic's framework itself. This vision is shared by classical empiricism and by doctrines such as ‘logical atomism’.
1903B. Russell Princ. Math. i. 3 Pure Mathematics is the class of all propositions of the form ‘p implies q’, where p and q are propositions containing one or more variables, the same in the two propositions, and neither p nor q contains any constants except logical constants. And logical constants are all notions definable in terms of the following: Implication, the relation of a term to a class of which it is a member, the notion of such that, the notion of relation, and such further notions as may be involved in the general notion of propositions of the above form. 1914― Our Knowl. External World vii. 208 Such words as or, not, if, there is, identity, greater, plus, nothing, everything, function, and so on, are not names of definite objects, like ‘John’..but are words which require a context in order to have meaning... ‘Logical constants’, in short, are not entities. 1922tr. Wittgenstein's Tractatus 69 My fundamental thought is that the ‘logical constants’ do not represent. That the logic of the facts cannot be represented. 1958G. J. Warnock Eng. Philos. since 1900 x. 125 We thus get a distinction between so-called ‘logical constants’, the irreplaceable words on which the validity of general patterns of inference depends, and items of non-logical vocabulary. 1965B. Mates Elem. Logic iv. 49 The logical constants occurring in ϕ are understood in the way usual among logicians (i.e., ‘{logicor}’ as standing for ‘or’, ‘—’ for ‘not’, the universal quantifier for ‘all’, etc.).
1883F. H. Bradley Princ. Logic 236 To show a new relation of elements in a logical construction is demonstration in the sense of reasoning. 1914B. Russell Our Knowl. External World iv. 101 The only justification possible must be one which exhibits matter as a logical construction from sense-data. 1936A. J. Ayer Lang., Truth & Logic iii. 73 The English State..is a logical construction out of individual people. 1956J. O. Urmson Philos. Analysis iii. 36 If ‘X’ is an incomplete symbol then Xs are logical constructions. Thus if the expression ‘the average man’ is an incomplete symbol we may say that the average man is a logical construction.
1936A. J. Ayer Lang., Truth & Logic 10 Our own logical empiricism to be distinguished from positivism. 1937Mind XLVI. 345 Logical Empiricists are not attempting to be metaphysical, when they distinguish between language and reality. On the contrary, the distinction refers only to certain rules of usage for statements and modes of speech. Since we have investigated the rules of speech in empirical sciences, we are justified in calling our viewpoint ‘Logical Empiricism’. 1966J. J. Katz Philos. of Lang. iii. 16 The chief reason for this failure on the part of logical empiricism..and ordinary language philosophy..was that both were governed in their inferences..by an assumption about the nature of language.
1936Mind XLV. 545 J. Somerville [in] ‘The Social Ideas of the Wiener Kreis's International Congress’ reflects on the Paris Congress 1935, [and] announces that the ‘logical positivists’ desire to repudiate Comte and to be henceforth known as ‘scientific’ or ‘logical’ empiricists. 1967Philos. XLII. 293 A failure to work out in detail the consequences of logical empiricist principles for ethics.
1843Mill Logic I. iii. v. 404 This tendency shows itself very visibly in the different logical fictions which are resorted to even by philosophers... Thus, rather than say that the earth causes the fall of bodies, they ascribe it to a force exerted by the earth, or an attraction by the earth. 1918B. Russell in Monist XXVIII. 512, I believe that series and classes are of the nature of logical fictions. 1933L. S. Stebbing Mod. Introd. Logic (ed. 2) 502 To say that the table is a logical fiction (or construction) is not to say that the table is fictitious..it is rather to deny that, in any ordinary sense, it is an object at all. Ibid., ‘Logical fiction’ may be taken to be an unfortunate synonym for ‘logical construction’.
1840Mill in Westm. Rev. XXXIII. 266 A truth..to be believed in opposition to all that appears proof to the mere understanding; nay, the more to be believed, because it cannot be put into words and into the logical form of a proposition without a contradiction in terms. 1967A. E. Blumberg in Encycl. Philos. V. 13/2 Logic confines itself to those arguments whose validity rests exclusively on the logical form of the statements composing them... There is still no fully satisfactory account of logical form.
1922tr. Wittgenstein's Tractatus 55 A symbolism..which obeys the rules of logical grammar—of logical syntax. 1962L. J. Cohen Diversity of Meaning iii. 81 The most obvious fault in the doctrine of logical grammar is that it suggests the conceptual study of meanings to be concerned with something that is timeless and unchanging.
1937Atlantic Monthly CLIX. 49/2 The logical-grammatical construction involved is so commonly mishandled in current American speech and print.
1887A. Seth Hegelianism v. 172 In the first sense..development means simply logical implication. 1904B. Russell in Mind XIII. 209 It would seem that..logical implication is a simple notion, into whose composition the notion of terms does not enter. 1934Cohen & Nagel Introd. Logic i. 9 (heading) Logical implication does not depend on the truth of our premises.
1870W. S. Jevons in Proc. R. Soc. XVIII. 167 To explain the nature of the logical machine alluded to, it may be pointed out that the third of the fundamental Laws of Thought allows us to affirm of any object one or the other of two contradictory attributes. 1883F. H. Bradley Princ. Logic 344 We shall discuss the Indirect Method, and with it the claims of the Logical Machine. 1943Mind LII. 319 He is thus stymied at the outset, and being neither a logical machine nor an esthetic idiot he is likely to feel uncomfortable about it.
1868C. S. Peirce in Proc. Amer. Acad. Arts & Sci. VII. 251 Let a, b denote the individuals contained at once under the classes a and b... If a and b were independent events, a, b would denote the event whose probability is the product of the probabilities of each. On the strength of this analogy..the operation indicated by the comma may be called logical multiplication. 1903,1970Logical multiplication [see logical addition above].
1885C. S. Peirce in Amer. Jrnl. Math. VII. 186, I prefer not to assign determinate values to f and v, nor to identify the logical operations with any special arithmetical ones. 1932Lewis & Langford Symbolic Logic i. 7 It would have coincided with what we now know as symbolic logic. That is, it would have been an organon of reasoning in general, developed in ideographic symbols and enabling the logical operations to be performed according to precise rules. 1960M. G. Say et al. Analogue & Digital Computers vii. 165 A zero input digit to this unit gives a one-digit output and a one-digit input gives a zero output. This is the logical operation ‘not’. 1970Logical operation [see logical addition above].
1904W. James Ess. Radical Empiricism (1912) i. 11 ‘Representative’ theories of perception avoid the logical paradox, but on the other hand they violate the reader's sense of life, which knows no intervening mental image. 1954I. M. Copi Symbolic Logic 332 These two kinds of paradoxes were first explicitly distinguished by F. P. Ramsey in 1926. Since then those of the first kind have been known as ‘logical paradoxes’. 1967J. van Heijenoort in Encycl. Philos. V. 45/2 In logic the word [sc. paradox] has taken on a more precise meaning. A logical paradox consists of two contrary, or even contradictory, propositions to which we are led by apparently sound arguments.
1931Blumberg & Feigl in Jrnl. Philos. XXVIII. 281 To facilitate criticism and forestall even more unfortunate attempts at labelling this aspect of contemporary European philosophy, we shall employ the term ‘logical positivism’. 1934Philos. Rev. XLIII. 125 The logical positivism of the Vienna Circle..is based..upon this consideration of empirical meaning. 1968M. Black Labyrinth of Lang. vi. 147 Logical Positivism has seen its best days.
1931Jrnl. Philos. XXVIII. 291 The principle of causality is for the logical positivist not a categorical necessity of thought. 1967J. Passmore in Encycl. Philos. V. 55/1 The logical positivists ordinarily took for granted the substantial truth of contemporary Science. Thus, it was a matter of vital concern to them when it became apparent that the verifiability principle would rule out as meaningless all scientific laws.
1868C. S. Peirce in Proc. Amer. Acad. Arts & Sci. VII. 411 The numerical rank of a logical product depends on the identity or diversity..of parts of the factors. 1903B. Russell Princ. Math. ii. 21 Most of the propositions of the class-calculus are easily deduced from those of the propositional calculus. The logical product or common part of two classes a and b is the class of x's such that the logical product of ‘x is an a’ and ‘x is a b’ is true. Similarly we can define the logical sum of two classes (a or b). 1955A. N. Prior Formal Logic i. i. 7 We may also have a conjunction or logical product of more than two propositions, the analogy with arithmetical multiplication still holding. 1959Logical product [see logical sum below].
1871A. C. Fraser Life Berkeley ii. 39, I have tried elsewhere..to explain the logical structure of the Essay on Vision. 1918B. Russell in Monist XXVIII. 510 The first thing to do would be to discover the kinds of atoms out of which logical structures are composed. 1943Mind LII. 26 Linguistic structure, though at times it conceals or distorts, has to be taken as capable of revealing logical structure, otherwise the study of logic would be impossible. 1970L. J. Cohen Implications Induction i. 6 Many propositions are never hypothesised at all, even if alike in logical structure to those that are.
1898Mind VII. 34 (heading) On the logical subject of the proposition. 1903B. Russell Princ. Math. iv. 44 Every term..is a logical subject. 1933[see grammatical a. 1 b]. 1965N. Chomsky Aspects of Theory of Syntax i. 23 In (8i) [sc. ‘I persuaded a specialist to examine John’] the phrase ‘a specialist’ is the Direct-Object of the Verb Phrase and the logical Subject of the embedded sentence. Ibid. iv. 163 It seems that beyond the notions of surface structure..and deep structure (such as ‘logical subject’), there is some still more abstract notion of ‘semantic function’ still unexplained.
1868C. S. Peirce in Proc. Amer. Acad. Arts & Sci. VII. 411 The numerical rank of a logical sum depends on the identity or diversity..of the integrant parts. 1903[see logical product above]. 1959C. V. L. Smith Electronic Digital Computers ii. 32 Given two binary words..it is possible to generate a third word each bit of which is the logical sum or the logical product or, indeed, any Boolean function of the bits in the corresponding position of the given words. Operations of this sort may be called ‘logical operations’. 1963G. T. Kneebone Math. Logic ii. 53 In older accounts of symbolic logic, the terms ‘logical sum’ and ‘logical product’ are often used where ‘disjunction’ and ‘conjunction’ would now be preferred. There is indeed an analogy between the arithmetical operations of addition and multiplication.
1922Logical syntax [see logical grammar above]. 1934R. Carnap in Philos. Sci. I. 9 By the ‘logical syntax’ (or also briefly ‘syntax’) of a language we shall understand the system of the formal (i.e. not referring to meaning) rules of that language, as well as..the consequences of these rules. 1945Mind LIV. 172 The weaknesses of the argument might be due in part at least to a certain poverty in the technical equipment of ‘logical syntax’. 1970L. J. Cohen Implications Induction i. 6 Some elementary principles in the logical syntax of experimental support.
1818–19Coleridge Philos. Lect. (1949) ix. 276 This necessarily led men..to doubt whether a logical truth was necessarily an existential one, i.e. whether because a truth was logically consistent it must be necessarily existent. 1877W. S. Jevons Princ. Sci. (ed. 2) viii. 153 Nothing is more certain than logical truth. 1943Mind LII. 272 An exhaustive formulation of logical truth remains a worthy undertaking.
1940B. Russell Inquiry into Meaning & Truth 20 We pass from the primary to the secondary language by adding what I shall call ‘logical words’, such as ‘or’, ‘not’, ‘some’, and ‘all’, together with the words ‘true’ and ‘false’ as applied to sentences in the object-language. 1958S. E. Toulmin Uses Argument iv. 149 The validity of syllogisms being closely bound up with the proper distribution of logical words within the statements composing them. 1972Sci. Amer. Sept. 82/3 Language performs this miraculous function largely through such little particles as ‘if’, ‘when’, ‘not’, ‘therefore’, ‘all’ and ‘some’, which have been called logical words because they account for the ability of language to formulate logical inferences (also known as syllogisms). |