The Essentials of Logic, Being Ten Lectures on Judgment and Inference

Lecture Iv Types of Judgment, and the General

CONDITIONS INVOLVED IN ASSERTION

1. Correspondence between Types of Judgment and Nature of Objects as Knowledge 61 a. Impersonal Judgment 61 b. Perceptive Judgment 62 c. Proper Names in Judgment 64 d. Abstract Judgment 65

2. The General Definition of Judgment 66 i. What is implied in claiming Truth 67 ii. By what means the claim is made 69 iii. The kind of Ideas which can claim Truth 74 a. Idea as Psychical Presentation 74 b. Idea as Identical Reference 74

Lecture V the Proposition and the Name

1. Judgment translated into Language 80

2. Proposition and Sentence 82

3. Difference between Proposition and Judgment 82

4. “Parts of Speech” 85

5. Denotation and Connotation 88

6. Have Proper Names Connotation? 91

7. Inverse Ratio of Connotation and Denotation 94

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Lecture Vi Parts of the Judgment, and Its Unity

1. Parts of the Judgment 98

2. Copula 99

3. Are Subject and Predicate necessary? 100

4. Two Ideas or Things 101 a. Two Ideas 102 i. Mental Transition 102 ii. Absence of Assertion 103 b. Two Things 104

5. Distinction between Subject and Predicate 107

Lecture Vii the Categorical and the Hypothetical

JUDGMENTS

1. Some Criticisms on the ordinary scheme of Judgment 112 a. Why we need a Scheme 112 b. The Common Scheme 113

2. Which Judgments are Categorical? 116 (1) The “Particular” Judgment 116 a. Natural Meaning 116 b. Limited Meaning 117 (2) “Singular” Judgment 118 (3) “Universal” Judgment 119 (4) “Hypothetical” Judgment 121 (5) “Disjunctive” Judgment 123

Lecture Viii Negation, and Opposition of Judgments

1. Distinction between Contrary and Contradictory Opposition 126

2. Contrary Negation 128

3. Why use Negation? 130

4. Stage of Significant Negation; Combination of Contrary and Contradictory 132

5. Negative Judgment expressing Fact 134

6. Operation of the Denied Idea 135

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Lecture Ix Inference and the Syllogistic Forms

1. Inference in General 137

2. Conditions of the Possibility of Inference 139

3. System the ultimate condition of Inference 140

4. Immediate Inference 141

5. Number of Instances 142

6. Figures of Syllogism, illustrating Progress from Guess-work to Demonstration 146

Lecture X Induction, Deduction, and Causation

1. Induction 151 a. By simple Enumeration 151 b. Enumeration always has a Ground 152 c. Perfect Induction 152 d. System 153 e. Analogy as Step towards System 155 f. Negative Instance 158 g. Classification and Generalisation 159 h. Hypothesis 161

2. Deduction 162 a. Subsumption 163 b. Construction 163

3. Causation 164

4. The Postulate of Knowledge 165

5. Conclusion 166

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Lecture I the Problem of Logic

Difficulty of the science

1. There is no science more difficult than that on which we are entering in these lectures. It is worth while to discuss the nature of this difficulty. It is a question of interest rather than of intricacy. All sciences have, perhaps, much the same possibilities of broad theory and subtle analysis. But Logic stands alone in the difficulty with which the student sustains his persuasion that its point of view is worth applying.

In most other sciences, even in the philosophical sciences, there is a continual stimulus to sense-perception, to curiosity, to human interest. The learner is called upon to dissect animals or plants, to undertake delicate manipulations with beautifully contrived instruments, to acquaint himself with the history of nations, with the genesis of worlds, with strange and novel speculations upon the nature of space, or with the industry and well-being of various classes among mankind at the present day. And these elements of novelty, these stimulations of sense-perception or of practical interest, carry us forward imperceptibly, and sustain our {2} eagerness to analyse and combine in theoretic completeness the novel matter thus constantly impinging upon us.

In Philosophy, and more especially in Logic, we can promise little or nothing of this kind. The teacher of Philosophy, from Socrates downwards, has talked about common things, things already familiar to his hearers. And although he calls upon them to think of these things in a peculiar way, and from an unaccustomed point of view, yet it is likely to be felt that he is demanding a new effort, without supplying a new interest. And it is a common experience, that after a time the mind rebels against this artificial attitude, which fatigues without instructing, if we have accustomed ourselves to understand by instruction the accumulation of new sense-perceptions and the extension of historical or scientific vision over a wider superficial area.

Now this I cannot help, and I will not disguise. In Philosophy, and in Logic above all, it must be so. The whole point and meaning of the study is that in it we re-traverse familiar ground, and survey it by unfamiliar processes. We do not, except accidentally, so much as widen our mental horizon. For those who care to understand, to trace the connecting principles and functions that permeate our intellectual world, there is indeed an interest of a peculiar kind. But even experienced students will occasionally feel the strain of attending to difficult distinctions, entirely without the excitement of novelty in sense-perception or of a practical bearing upon human life. It is this that makes Logic probably the hardest of all the sciences.

{3} The problem stated

2. We cannot hope to vanquish this difficulty unless we face it boldly from the first. There are in the old-fashioned Logic-books tricks and puzzles, fallacies and repartees, which can in some degree be made amusing; but of these I do not intend to speak. The course by which alone I can hope honestly to awaken a true logical interest among any who may be quite unfamiliar with the subject, is to approach the matter descriptively, and try to set before you fully and fairly what the problem is which the process of knowledge has to meet. And then it may be possible to claim a genuine theoretical curiosity--none the less genuine that it may be tinged with a sympathy for man’s common birthright of intelligence--for the detailed explanation of the means by which this problem is solved from day to day. Such an explanation is the science of Logic.

The problem may be thus introduced. Several of those present have, I believe, attended a previous course of lectures on Psychology. They have learned, I presume, to think of the mind as the course of consciousness, a continuous connected presentation, more or less emphasising within it various images, and groups of images and ideas, which may be roughly said to act and re-act upon each other, to cohere in systems, and to give rise to the perception of self. This course of consciousness, including certain latent elements, the existence of which it is necessary to assume, is an individual mind, attached to a particular body, and so far as we know, not separable from the actions and affections of that body. What is the connection between such a course of consciousness in any individual, and the world as that individual knows and wills it? This is the point at {4} which Psychology passes into Logic. Psychology treats of the course of ideas and feelings; Logic of the mental construction of reality. How does the course of my private ideas and feelings contain in it, for me, a world of things and persons which are not merely in my mind?

World as Idea

3. Schopenhauer called his great work, The World as Will and Idea. Leaving out Will for the moment, let us consider the world “as Idea.”

“‘The world is my idea;’ this is a truth which holds good for everything that lives and knows, though man alone can bring it into reflective and abstract consciousness. If he really does this, he has attained to philosophical wisdom. It then becomes clear and certain to him that what he knows is not a sun and an earth, but only an eye that sees a sun, a hand that feels an earth; that the world which surrounds him is there only as an idea, i.e. only in relation to something else, the consciousness which is himself. If any truth can be asserted a priori, it is this; for it is the expression of the most general form of all possible and thinkable experience: a form which is more general than time, space, or causality, for they all pre-suppose it.

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“No truth, therefore, is more certain, more independent of all others, and less in need of proof than this, that all that exists for knowledge, and, therefore, this whole world, is only object in relation to subject, perception of a perceiver, in a word, idea. This is obviously true of the past and the future, as well as of the present, of what is farthest off, as of {5} what is near; for it is true of time and space themselves, in which alone these distinctions arise. All that in any way belongs or can belong to the world is inevitably thus conditioned through the subject and exists only for the subject. The world is idea.”

E. Tr. (Trubner, 1883).

Schopenhauer, op. cit. beginning.

The world, then, for each of us, exists in the medium of our mind. It is a sort of building, of which the materials are our ideas and perceptions.

The “world”

4. So much for “idea.” What do we mean by “world”? A succession of images passing before us, or rather making up our consciousness, like a dream, is not a world. The term is very expressive; it is a favourite word in Shakespeare. When the courtier says —

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