Chapter I: Preface

In this little treatise two things are attempted that at first might appear incompatible. One of them is to put the study of logical formulae on a historical basis. Strangely enough, the scientific evolution of logical forms, is a bit of history that still awaits the zeal and genius of some great scholar. I have neither ambition nor qualification for such a _magnum opus_, and my life is already more than half spent; but the gap in evolutionary research is so obvious that doubtless some younger man is now at work in the field unknown to me. All that I can hope to do is to act as a humble pioneer according to my imperfect lights. Even the little I have done represents work begun more than twenty years ago, and continuously pursued for the last twelve years during a considerable portion of my time.

The other aim, which might at first appear inconsistent with this, is to increase the power of Logic as a practical discipline. The main purpose of this practical science, or scientific art, is conceived to be the organisation of reason against error, and error in its various kinds is made the basis of the division of the subject. To carry out this practical aim along with the historical one is not hopeless, because throughout its long history Logic has been a practical science; and, as I have tried to show at some length in introductory chapters, has concerned itself at different periods with the risks of error peculiar to each.

To enumerate the various books, ancient and modern, to which I have been indebted, would be a vain parade. Where I have consciously adopted any distinctive recent contribution to the long line of tradition, I have made particular acknowledgment. My greatest obligation is to my old professor, Alexander Bain, to whom I owe my first interest in the subject, and more details than I can possibly separate from the general body of my knowledge.

W. M.

ABERDEEN, _January, 1893_.

Since these sentences were written, the author of this book has died; and Professor Minto's _Logic_ is his last contribution to the literature of his country. It embodies a large part of his teaching in the philosophical class-room of his University, and doubtless reflects the spirit of the whole of it.

Scottish Philosophy has lost in him one of its typical representatives, and the University of the North one of its most stimulating teachers. There have been few more distinguished men than William Minto in the professoriate of Aberdeen; and the memory of what he was, of his wide and varied learning, his brilliant conversation, his urbanity, and his rare power of sympathy with men with whose opinions he did not agree, will remain a possession to many who mourn his loss.

It will be something if this little book keeps his memory alive, both amongst the students who owed so much to him, and in the large circle of friends who used to feel the charm of his personality.

WILLIAM KNIGHT.

_GENERAL PLAN OF THE SERIES._

_This Series is primarily designed to aid the University Extension Movement throughout Great Britain and America, and to supply the need so widely felt by students, of Text-books for study and reference, in connexion with the authorised Courses of Lectures._

_The Manuals differ from those already in existence in that they are not intended for School use, or for Examination purposes; and that their aim is to educate, rather than to inform. The statement of details is meant to illustrate the working of general laws, and the development of principles; while the historical evolution of the subject dealt with is kept in view, along with its philosophical significance._

_The remarkable success which has attended University Extension in Britain has been partly due to the combination of scientific treatment with popularity, and to the union of simplicity with thoroughness. This movement, however, can only reach those resident in the larger centres of population, while all over the country there are thoughtful persons who desire the same kind of teaching. It is for them also that this Series is designed. Its aim is to supply the general reader with the same kind of teaching as is given in the Lectures, and to reflect the spirit which has characterised the movement, viz., the combination of principles with facts, and of methods with results._

_The Manuals are also intended to be contributions to the Literature of the Subjects with which they respectively deal, quite apart from University Extension; and some of them will be found to meet a general rather than a special want._

_They will be issued simultaneously in England and America. Volumes dealing with separate sections of Literature, Science, Philosophy, History, and Art have been assigned to representative literary men, to University Professors, or to Extension Lecturers connected with Oxford, Cambridge, London, and the Universities of Scotland and Ireland._

_A list of the works in this Series will be found at the end of the volume._

CONTENTS.

INTRODUCTION.

I.
PAGE

The Origin and Scope of Logic, 1

II.

Logic as a Preventive of Error or Fallacy--The Inner
Sophist, 17

III.

The Axioms of Dialectic and of Syllogism, 29

BOOK I.

THE LOGIC OF CONSISTENCY--SYLLOGISM AND
DEFINITION.

PART I.

THE ELEMENTS OF PROPOSITIONS.

CHAPTER I.

General Names and Allied Distinctions, 43

CHAPTER II.

The Syllogistic Analysis of Proposition, into Terms. (1)
The Bare Analytic Forms. (2) The Practice of Syllogistic
Analysis. (3) Some Technical Difficulties, 62

PART II.

DEFINITION.

CHAPTER I.

(1) Imperfect Understanding of Words. (2) Verification of
the Meaning--Dialectic. (3) Fixation of the Meaning--Division
or Classification, Definition, Naming, 82

CHAPTER II.

The Five Predicables--Verbal and Real Predication, 105

CHAPTER III.

Aristotle's Categories, 112

CHAPTER IV.

The Controversy about Universals--Difficulties concerning
the Relation of General Names to Thought and to Reality, 120

PART III.

THE INTERPRETATION OF PROPOSITIONS.

CHAPTER I.

Theories of Predication--Theories of Judgment, 131

CHAPTER II.

The "Opposition" of Propositions--The Interpretation of
"No," 139

CHAPTER III.

The Implication of Propositions--Immediate Formal Inference
--Eduction, 146

CHAPTER IV.

The Counter-Implication of Propositions, 156

PART IV.

THE INTERDEPENDENCE OF PROPOSITIONS.

CHAPTER I.

The Syllogism, 167

CHAPTER II.

The Figures and Moods of the Syllogism. (1) The First
Figure. (2) The Minor Figures and their Reduction to
the First. (3) Sorites, 173

CHAPTER III.

The Demonstration of the Syllogistic Moods--The Canons
of the Syllogism, 185

CHAPTER IV.

The Analysis of Arguments into Syllogistic Forms, 196

CHAPTER V.

Enthymemes, 205

CHAPTER VI.

The Utility of the Syllogism, 209

CHAPTER VII.

Conditional Arguments--Hypothetical Syllogism, Disjunctive
Syllogism and Dilemma, 215

CHAPTER VIII.

Fallacies in Deductive Argument--_Petitio Principii_ and
_Ignoratio Elenchi_, 226

CHAPTER IX.

Formal or Aristotelian Induction--Inductive Argument--The
Inductive Syllogism, 235

BOOK II.

INDUCTIVE LOGIC, OR THE LOGIC OF SCIENCE.

Introduction, 243

CHAPTER I.

The Data of Experience as Grounds of Inference or Rational
Belief, 273

CHAPTER II.

Ascertainment of Simple Facts in their Order--Personal
Observation--Hearsay Evidence--Method of Testing
Traditional Evidence, 285

CHAPTER III.

Ascertainment of Facts of Causation. (1) _Post Hoc Ergo
Propter Hoc._ (2) Meaning of Cause--Methods of Observation
--Mill's Experimental Methods, 295

CHAPTER IV.

Method of Observation--Single Difference. (1) The Principle
of Single Difference. (2) Application of the Principle, 308

CHAPTER V.

Methods of Observation--Elimination--Single Agreement.
(1) The Principle of Elimination. (2) The Principle of
Single Agreement. (3) Mill's "Joint Method of Agreement
and Difference," 318

CHAPTER VI.

Methods of Observation--Minor Methods. (1) Concomitant
Variations. (2) Single Residue, 329

CHAPTER VII.

The Method of Explanation. (1) The Four Stages of Orderly
Procedure. (2) Obstacles to Explanation--Plurality of Causes
and Intermixture of Effects. (3) The Proof of a Hypothesis, 334

CHAPTER VIII.

Supplementary Methods of Investigation. (1) The Maintenance
of Averages--Supplement to the Method of Difference.
(2) The Presumption from Extra-Casual Coincidence, 351

CHAPTER IX.

Probable Inference to Particulars--The Measurement of
Probability, 362

CHAPTER X.

Inference from Analogy, 367