Logic: Deductive and Inductive

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Carveth Read. Logic: Deductive and Inductive

PREFACE

CHAPTER I. INTRODUCTORY

CHAPTER II. GENERAL ANALYSIS OF PROPOSITIONS

CHAPTER III. OF TERMS AND THEIR DENOTATION

CHAPTER IV. THE CONNOTATION OF TERMS

CHAPTER V. THE CLASSIFICATION OF PROPOSITIONS

CHAPTER VI. CONDITIONS OF IMMEDIATE INFERENCE

CHAPTER VII. IMMEDIATE INFERENCES

CHAPTER VIII. ORDER OF TERMS, EULER'S DIAGRAMS, LOGICAL EQUATIONS, EXISTENTIAL IMPORT OF PROPOSITIONS

CHAPTER IX. FORMAL CONDITIONS OF MEDIATE INFERENCE

CHAPTER X. CATEGORICAL SYLLOGISMS

CHAPTER XI. ABBREVIATED AND COMPOUND ARGUMENTS

CHAPTER XII. CONDITIONAL SYLLOGISMS

CHAPTER XIII. TRANSITION TO INDUCTION

CHAPTER XIV. CAUSATION

CHAPTER XV. INDUCTIVE METHOD

CHAPTER XVI. THE CANONS OF DIRECT INDUCTION

CHAPTER XVII. COMBINATION OF INDUCTION WITH DEDUCTION

CHAPTER XVIII. HYPOTHESES

CHAPTER XIX. LAWS CLASSIFIED; EXPLANATION; CO-EXISTENCE; ANALOGY

CHAPTER XX. PROBABILITY

CHAPTER XXI. DIVISION AND CLASSIFICATION

CHAPTER XXII. NOMENCLATURE, DEFINITION, PREDICABLES

CHAPTER XXIII. DEFINITION OF COMMON TERMS

CHAPTER XXIV. FALLACIES

QUESTIONS

I. TERMS, ETC

II. PROPOSITIONS AND IMMEDIATE INFERENCE

III. SYLLOGISM AND MEDIATE INFERENCE

IV. INDUCTION, ETC

V. MISCELLANEOUS

Отрывок из книги

§ 1. Logic is the science that explains what conditions must be fulfilled in order that a proposition may be proved, if it admits of proof. Not, indeed, every such proposition; for as to those that declare the equality or inequality of numbers or other 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 in conversation, in literature, in politics, and even in sciences so far as they are not treated mathematically (say, Botany and Psychology); 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, or false, or doubtful. When propositions are expressed with the universality and definiteness that belong to scientific statements, they are called laws; and laws, so far as they are not laws of quantity, are tested by the principles of Logic, if they at all admit of proof.

But it is plain that the process of proving cannot go on for ever; something must be taken for granted; and this is usually considered to be the case (1) with particular facts that can only be perceived and observed, and (2) with those highest laws that are called 'axioms' or 'first principles,' of which we can only say that we know of no exceptions to them, that we cannot help believing them, and that they are indispensable to science and to consistent thought. Logic, then, may be briefly defined as the science of proof with respect to qualitative laws and propositions, except those that are axiomatic.

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To distinguish Logic from Psychology is most important in connection with Conceptualism. Concepts and Judgments being mental acts, or products of mental activity, it is often thought that Logic must be a department of Psychology. It is recognised of course, that Psychology deals with much more than Logic does, with sensation, pleasure and pain, emotion, volition; but in the region of the intellect, especially in its most deliberate and elaborate processes, namely, conception, judgment, and reasoning, Logic and Psychology seem to occupy common ground. In fact, however, the two sciences have little in common except a few general terms, and even these they employ in different senses. It is usual to point out that Psychology tries to explain the subjective processes of conception, judgment and reasoning, and to give their natural history; but that Logic is wholly concerned with the results of such processes, with concepts, judgments and reasonings, and merely with the validity of the results, that is, with their truth or consistency; whilst Psychology has nothing to do with their validity, but only with their causes. Besides, the logical judgment (in Formal Logic at least) is quite a different thing from the psychological: the latter involves feeling and belief, whereas the former is merely a given relation of concepts. S is P: that is a model logical judgment; there can be no question of believing it; but it is logically valid if M is P and S is M. When, again, in Logic, one deals with belief, it depends upon evidence; whereas, in Psychology belief is shown to depend upon causes which may have evidentiary value or may not; for Psychology explains quite impartially the growth of scientific insight and the growth of prejudice.

(c) Mill, Bain, and Venn are the chief Materialist logicians; and to guard against the error of confounding Materialism in Logic with the ontological doctrine that nothing exists but Matter, it may suffice to remember that in Metaphysics all these philosophers are Idealists. Materialism in Logic consists in regarding propositions as affirming or denying relations (cf. § 5) between matters-of-fact in the widest sense; not only physical facts, but ideas, social and moral relations; it consists, in short, in attending to the meaning of propositions. It treats the first principles of Contradiction and Causation as true of things so far as they are known to us, and not merely as conditions or tendencies of thought; and it takes these principles as conditions of right thinking, because they seem to hold good of Nature and human life.

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