Deductive Logic | Page 2

extent to my ingenious friend, the Rev. W. J. Priest of Merton
College.
My thanks are due also to my friend and former pupil, Mr. Gilbert
Grindle, Scholar of Corpus, who has been at the pains to compose an
index, and to revise the proofs as they passed through the press.
And last, but not least, I must set on record my gratitude to Commander
R. A. Stock, R.N., one of Her Majesty's Knights of Windsor, without
whose brotherly aid this work might never have been written, and
would certainly not have assumed exactly its present shape.
OXFORD,
October 22, 1888.

CONTENTS.
PREFACE.
INTRODUCTION, §§ 1-56.

PART I. Of Terms, §§ 57-171.
CHAP. I. Of the Term as distinguished from other words, §§ 57-76.

II. Of the Division of Things, §§ 77-85.
III. Of the Divisions of Terms, §§ 86-165.
IV. Of the Law of Inverse Variation of Extension and Intension, §§
166-171.

PART II. Of Propositions, §§ 172-185.
CHAP. I. Of the Proposition as distinguished from other Sentences, §§
172-185.
II. Of the Copula, §§ 186-201.
III. Of the Divisions of Propositions, §§ 202-273.
IV. Of the Distribution of Terms, §§ 274-294.
V. Of the Quantification of the Predicate, §§ 295-312.
VI. Of the Heads of Predicables, §§ 313-346.
VII. Of Definition, §§ 347-384.
VIII. Of Division, §§ 385-425.

PART III. Of Inferences, §§ 426-884.
CHAP. I. Of Inferences in general, §§ 426-441.
II. Of Deductive Inferences, §§ 442-448.
III. Of Opposition, §§ 449-478.

IV. Of Conversion, §§ 479-495.
V. Of Permutation, §§ 496-502.
VI. Of Compound Forms of Immediate Inference, §§ 503-532.
VII. Of Other Forms of Immediate Inference, §§ 533-539.
VIII. Of Mediate Inferences or Syllogisms, §§ 540-557.
IX. Of Mood and Figure, §§ 558-568.
X. Of the Canon of Reasoning, §§ 569-581.
XI. Of the General Rules of Syllogism, §§ 582-598.
XII. Of the Determination of the Legitimate Moods of Syllogism, §§
599-605.
XIII. Of the Special Rules of the Four Figures, §§ 606-620.
XIV. Of the Determination of the Moods that are valid in the Four
Figures, §§ 621-632.
XV. Of the Special Canons of the Four Figures, §§ 633-647.
XVI. Of the Special Uses of the Four Figures, §§ 648-655.
XVII. Of the Syllogism with Three Figures, §§ 656-666.
XVIII. Of Reduction, §§ 667-700.
XIX. Of Immediate Inference as applied to Complex Propositions, §§
701-730.
XX. Of Complex Syllogisms, §§ 731-743.
XXI. Of the Reduction of the Partly Conjunctive Syllogism, §§
744-752.

XXII. Of the Partly Conjunctive Syllogism regarded as all Immediate
Inference, §§ 753-759.
XXIII. Of the Disjunctive Syllogism, §§ 760-765.
XXIV. Of the Reduction of the Disjunctive Syllogism, §§ 766-769.
XXV. Of the Disjunctive Syllogism regarded as an Immediate
Inference, §§ 770-777.
XXVI. Of the Mixed Form of Complex Syllogism, §§ 778-795.
XXVII. Of the Reduction of the Dilemma, §§ 796-797.
XXVIII. Of the Dilemma regarded as an Immediate Inference, §§
798,799.
XXIX. Of Trains of Reasoning, §§ 800-826.
XXX. Of Fallacies, §§ 827-884.
EXERCISES.
INDEX.

INTRODUCTION.
§ 1. LOGIC is divided into two branches, namely--
(1) Inductive,
(2) Deductive.
§ 2. The problem of inductive logic is to determine the actual truth or
falsity of propositions: the problem of deductive logic is to determine
their relative truth or falsity, that is to say, given such and such
propositions as true, what others will follow from them.

§ 3. Hence in the natural order of treatment inductive logic precedes
deductive, since it is induction which supplies us with the general truths,
from which we reason down in our deductive inferences.
§ 4. It is not, however, with logic as a whole that we are here concerned,
but only with deductive logic, which may be defined as The Science of
the Formal Laws of Thought.
§ 5. In order fully to understand this definition we must know exactly
what is meant by 'thought,' by a 'law of thought,' by the term 'formal,'
and by 'science.'
§ 6. Thought, as here used, is confined to the faculty of comparison. All
thought involves comparison, that is to say, a recognition of likeness or
unlikeness.
§ 7. The laws of thought are the conditions of correct thinking. The
term 'law,' however, is so ambiguous that it will be well to determine
more precisely in what sense it is here used.
§ 8. We talk of the 'laws of the land' and of the 'laws of nature,' and it is
evident that we mean very different things by these expressions. By a
law in the political sense is meant a command imposed by a superior
upon an inferior and sanctioned by a penalty for disobedience. But by
the 'laws of nature' are meant merely certain uniformities among natural
phenomena; for instance, the 'law of gravitation' means that every
particle of matter does invariably attract every other