Logic, by Carveth Read potx

The Project Gutenberg EBook of Logic, by Carveth ReadThis eBook is for the use of anyone anywhere at no cost and with almost no restrictions whatsoever.. You may copy it, give it away or

The Project Gutenberg EBook of Logic, by Carveth Read

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anywhere at no cost and with

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Title: Logic

Deductive and Inductive

Author: Carveth Read

Release Date: May 23, 2006 [EBook #18440] Language: English

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LOGIC

DEDUCTIVE AND INDUCTIVE

First Edition, June 1898 (Grant

Richards.) Second Edition,

November 1901.

(Grant

Richards.) Third Edition, January

1906.

(A Moring

Ltd.) Reprinted, January 1908 (A Moring

Ltd.) Reprinted, May 1909 (A Moring

Ltd.)

Reprinted, July 1910 (A Moring

Ltd.) Reprinted, September

1911.

(A Moring

Ltd.) Reprinted, November

1912.

(A Moring

Ltd.) Reprinted, April 1913 (A Moring

Ltd.) Reprinted, May 1920 (Simpkin.)

LOGIC

DEDUCTIVE AND INDUCTIVE

BY

CARVETH READ,

M.A.

AUTHOR OF

"THE METAPHYSICS OF NATURE"

"NATURAL AND SOCIAL MORALS"

ETC

FOURTH EDITION

ENLARGED, AND PARTLY

REWRITTEN

SIMPKIN, MARSHALL, HAMILTON,KENT & CO LTD., 4 STATIONERS'

HALL COURT

LONDON, E.C.4

In this edition of my Logic, the text has

been revised throughout, several passageshave been rewritten, and some sectionsadded The chief alterations and additionsoccur in cc i., v., ix., xiii., xvi., xvii., xx

The work may be considered, on thewhole, as attached to the school of Mill;

to whose System of Logic, and to Bain's

Logic, it is deeply indebted Amongst the

works of living writers, the Empirical

Logic of Dr Venn and the Formal Logic

of Dr Keynes have given me mostassistance To some othersacknowledgments have been made as

occasion arose.

For the further study of contemporaryopinion, accessible in English, one mayturn to such works as Mr Bradley's

Principles of Logic, Dr Bosanquet's Logic; or the Morphology of Knowledge,

Prof Hobhouse's Theory of Knowledge,

J e v o n' s Principles of Science, and Sigwart's Logic Ueberweg's Logic, and

History of Logical Doctrine is invaluable

for the history of our subject The attitudetoward Logic of the Pragmatists orHumanists may best be studied in Dr

Schiller's Formal Logic, and in Mr Alfred Sidgwick's Process of Argument and recent Elementary Logic The second

part of this last work, on the "Risks ofReasoning," gives an admirably succinct

account of their position I agree with theHumanists that, in all argument, theimportant thing to attend to is the meaning,and that the most serious difficulties ofreasoning occur in dealing with the matterreasoned about; but I find that a purescience of relation has a necessary place

in the system of knowledge, and that theformulæ known as laws of contradiction,syllogism and causation are useful guides

in the framing and testing of arguments andexperiments concerning matters of fact.Incisive criticism of traditionarydoctrines, with some remarkablereconstructions, may be read in Dr

Mercier's New Logic.

In preparing successive editions of thisbook, I have profited by the comments of

my friends: Mr Thomas Whittaker, Prof.Claude Thompson, Dr Armitage Smith,

Mr Alfred Sidgwick, Dr Schiller, Prof.Spearman, and Prof Sully, have madeimportant suggestions; and I might haveprofited more by them, if the frame of mybook, or my principles, had been moreelastic

As to the present edition, usefulcriticisms have been received from Mr.S.C Dutt, of Cotton College, Assam, andfrom Prof M.A Roy, of Midnapore; and,especially, I must heartily thank mycolleague, Dr Wolf, for communicationsthat have left their impress upon nearlyevery chapter

Carveth Read

August, 1914

§2.General character of proof 2

§3.Division of the subject 5

§1.Propositions and Sentences 16

§2.Subject, Predicate and Copula 17

§3.Compound Propositions 17

§4.Import of Propositions 19

§5.Form and Matter 22

§6.Formal and Material Logic 23

§7.Symbols used in Logic 24

§2.Logic, Grammar and Rhetoric 28

§3.Words are Categorematic or

Syncategorematic 29

§4.Terms Concrete or Abstract 30

§5.Concrete Terms, Singular,

General or Collective 33

CHAPTER IV

THE CONNOTATION OF TERMS

§1.Connotation of General Names 37

§2.Question of Proper Names 38

other Singular Names (p 40)

§3.Question of Abstract Terms 40

§4.Univocal and Equivocal Terms 41

Connotation determined by the

§8.Positive and Negative Terms 50

Infinites; Privitives; Contraries

§7.Contradictory Opposition 87

§8.Sub-contrary Opposition 88

§9.The Square of Opposition 89

§10.Secondary modes of Immediate

Syllogism; Middle Term;

Minor Term; Major Term;

Minor and Major Premise (p

109); Illicit Process (p 110);

Distribution of the Middle (p

110); Negative Premises (p

112); Particular Premises (p

§3.Dictum de omni et nullo 115

§4.Syllogism in relation to the

§6.Ostensive Reduction and the

§9.Uses of the several Figures 134

§10.Scientific Value of Reduction 135

§11.Euler's Diagrams for the

§1.The Hypothetical Syllogism 147

§2.The Disjunctive Syllogism 152

Real General Propositions

assert more than has been

directly observed

160

Hence, formally, a Syllogism's

Premises seem to beg the

Conclusion

162

§4

Materially, a Syllogism turns

upon the resemblance of the

Minor to the Middle Term and

thus extends the Major Premise

Analysis of the Uniformity of

Nature, considered as the

formal ground of all reasoning

169

§8.Grounds of our belief in

Uniformity 173

How strictly the conception of

Cause can be applied depends

upon the subject under

Some condition, but not the

whole cause, may long precedethe Effect; and some co-effect, 187

but not the whole effect, may

long survive the Cause

§6

Mechanical Causes and the

homogeneous Intermixture of

Effects; Chemical Causes and

the heteropathic Intermixture ofEffects

§4.Imperfect Induction methodical

or immethodical

197

§5

Observation and Experiment,

the material ground of

Induction, compared

198

§6.The principle of Causation is

the formal ground of Induction 201

§7

The Inductive Canons are

derived from the principle of

Causation, the more readily to

detect it in facts observed

Agreement may show

connection without direct

Causation (p 209)

§2.The Canon of Agreement in

Presence and in Absence 212

It tends to disprove a Plurality

of Causes (p 213)

§3.The Canon of Difference 216

May be applied to observations(p 221)

§4.The Canon of Variations 222

How related to Agreement and

§5.The Canon of Residues 232

Deduction with Induction 238

§3.The Direct Deductive (or

§7.The Comparative Method 255

§8.Historical Evidence 261

CHAPTER XVIII

HYPOTHESES

§1.Hypothesis defined and

distinguished from Theory 266

adequate to its pretensions (p

272); Exceptio probat regulam

(p 274)

(3) Every competing

Hypothesis must be excluded

Axioms; Primary Laws;

Secondary Laws, Derivative or 288

§3.Secondary Laws trustworthy

only in 'Adjacent Cases' 293

§4.Secondary Laws of Succession

or of Co-existence 295Natural Kinds (p 296); Co-

existence of concrete things to

be deduced from Causation (p

§3.Probability depends upon

experience and statistics 313

§4.It is a kind of Induction, and

pre-supposes Causation 315

§5.Of Averages and the Law of

§6.Interpretation of probabilities 324

§3.Definition 352

§4.Rules for testing a Definition 352

§5.Every Definition is relative to a

Classification 353

§6.Difficulties of Definition 356

Proposals to substitute the Type(p 356)

§7.The Limits of Definition 357

§8.The five Predicables 358

Porphyry's Tree (p 361)

§9.Realism and Nominalism 364

§10.The Predicaments 366

CHAPTER XXIII

DEFINITION OF COMMON TERMS

§1.The rigour of scientific methodmust be qualified 369

§3.and an imperfect Terminology 374

§4.Maxims and precautions of

§1.Fallacy defined and divided 385

§2.Formal Fallacies of Deduction 385

§3.Formal Fallacies of Induction 388

§4.Material Fallacies classified 394

Fallacies, a natural rank growth

of the Human mind, not easy to

classify, or exterminate

403

LOGIC

CHAPTER I

INTRODUCTORY

§ 1 Logic is the science that explainswhat conditions must be fulfilled in orderthat a proposition may be proved, if itadmits of proof Not, indeed, every suchproposition; for as to those that declarethe equality or inequality of numbers orother magnitudes, to explain the conditions

of their proof belongs to Mathematics:

they are said to be quantitative But as to all other propositions, called qualitative,

like most of those that we meet with inconversation, in literature, in politics, and

even in sciences so far as they are nottreated mathematically (say, Botany andPsychology); propositions that merely tell

us that something happens (as that salt

dissolves in water), or that something has

a certain property (as that ice is cold): as

to these, it belongs to Logic to show how

we may judge whether they are true, orfalse, or doubtful When propositions areexpressed with the universality anddefiniteness that belong to scientificstatements, they are called laws; and laws,

so far as they are not laws of quantity, aretested by the principles of Logic, if they atall admit of proof

But it is plain that the process ofproving cannot go on for ever; somethingmust be taken for granted; and this is

usually considered to be the case (1) withparticular facts that can only be perceivedand observed, and (2) with those highestlaws that are called 'axioms' or 'firstprinciples,' of which we can only say that

we know of no exceptions to them, that wecannot help believing them, and that theyare indispensable to science and toconsistent thought Logic, then, may bebriefly defined as the science of proof

with respect to qualitative laws and

propositions, except those that areaxiomatic

§ 2 Proof may be of different degrees

or stages of completeness Absolute proofwould require that a proposition should beshown to agree with all experience andwith the systematic explanation of

experience, to be a necessary part of anall-embracing and self-consistentphilosophy or theory of the universe; but

as no one hitherto has been able to framesuch a philosophy, we must at present put

up with something less than absoluteproof Logic, assuming certain principles

to be true of experience, or at least to beconditions of consistent discourse,distinguishes the kinds of propositions thatcan be shown to agree with theseprinciples, and explains by what meansthe agreement can best be exhibited Suchprinciples are those of Contradiction(chap vi.), the Syllogism (chap ix.),Causation (chap xiv.), and Probabilities(chap xx.) To bring a proposition or anargument under them, or to show that itagrees with them, is logical proof

The extent to which proof is requisite,again, depends upon the present purpose:

if our aim be general truth for its ownsake, a systematic investigation isnecessary; but if our object be merely toremove some occasional doubt that hasoccurred to ourselves or to others, it may

be enough to appeal to any evidence that

is admitted or not questioned Thus, if aman doubts that some acids are compounds of oxygen, but grants that some compounds of oxygen are acids, he

may agree to the former proposition whenyou point out that it has the same meaning

as the latter, differing from it only in theorder of the words This is called proof

by immediate inference

Again, suppose that a man holds in his

hand a piece of yellow metal, which heasserts to be copper, and that we doubtthis, perhaps suggesting that it is reallygold Then he may propose to dip it invinegar; whilst we agree that, if it thenturns green, it is copper and not gold Ontrying this experiment the metal does turngreen; so that we may put his argument inthis way:—

Whatever yellow metal turns

green in vinegar is copper;

This yellow metal turns green in

directly that the yellow metal is copper;but it is admitted that any yellow metal iscopper that turns green in vinegar, and weare shown that this yellow metal has thatproperty.

Now, however, it may occur to us, thatthe liquid in which the metal was dippedwas not vinegar, or not pure vinegar, andthat the greenness was due to the impurity.Our friend must thereupon show by somemeans that the vinegar was pure; and thenhis argument will be that, since nothing butthe vinegar came in contact with the metal,the greenness was due to the vinegar; or,

in other words, that contact with thatvinegar was the cause of the metal turninggreen

Still, on second thoughts, we may

suspect that we had formerly conceded toomuch; we may reflect that, although it hadoften been shown that copper turned green

in vinegar, whilst gold did not, yet thesame might not always happen May it not

be, we might ask, that just at this moment,and perhaps always for the future goldturns, and will turn green in vinegar,whilst copper does not and never willagain? He will probably reply that this is

to doubt the uniformity of causation: hemay hope that we are not serious: he maypoint out to us that in every action of ourlife we take such uniformity for granted.But he will be obliged to admit that,whatever he may say to induce us to assent

to the principle of Nature's uniformity, hisarguments will not amount to logicalproof, because every argument in some

way assumes that principle He has come,

in fact, to the limits of Logic Just asEuclid does not try to prove that 'twomagnitudes equal to the same third areequal to one another,' so the Logician (assuch) does not attempt to prove theuniformity of causation and the otherprinciples of his science

Even when our purpose is to ascertainsome general truth, the results ofsystematic inquiry may have variousdegrees of certainty If Logic wereconfined to strict demonstration, it wouldcover a narrow field The greater part ofour conclusions can only be more or lessprobable It may, indeed, be maintained,not unreasonably, that no judgmentsconcerning matters of fact can be more

than probable Some say that all scientificresults should be considered as giving theaverage of cases, from which deviationsare to be expected Many matters can only

be treated statistically and by the methods

of Probability Our ordinary beliefs areadopted without any methodicalexamination But it is the aim, and it ischaracteristic, of a rational mind todistinguish degrees of certainty, and tohold each judgment with the degree ofconfidence that it deserves, consideringthe evidence for and against it It takes along time, and much self-discipline, tomake some progress toward rationality;for there are many causes of belief that arenot good grounds for it—have no value asevidence Evidence consists of (1)observation; (2) reasoning checked by