Summary of the Principal Themes
- Ch. 1.The relation of language to thought. Isolated notions express neither truth nor falsehood. Combination of notions or ideas in propositions or judgements essential before truth or error is possible.
- Ch. 2. Definition of a noun. Nouns simple or composite. Indefinite nouns. Cases of nouns.
- Ch. 3. Definition of a verb. Indefinite verbs. Tenses of verbs.
- Ch. 4. Definition of a sentence. Not every sentence a proposition.
- Ch. 5. Of simple and complex or composite propositions.
- Ch. 6. Of contradictory propositions.
- Ch. 7. Of universal, indefinite and particular affirmative and negative propositions. Of contrary as opposed to contradictory propositions.
- Ch. 8. Definition of single propositions.
- Ch. 9. Of propositions referring to the future, as opposed to propositions referring to the present time or to the past.
- Ch. 10. Affirmative and negative propositions arranged with a diagram in pairs. The correct position of the negative (οὐ). Of the truth and error of certain propositions. Of propositions with indefinite nouns or indefinite nouns and verbs. To transpose the subject and predicate makes no difference to the meaning of propositions.
- Ch. 11. Some propositions that seem to be simple are really compound. So are some dialectical questions. The nature of dialectical questions. Two simple propositions, which have the same subject, may be true; but we cannot of necessity combine the two predicates into one predicate. Several predicates holding of one subject, when taken by themselves and individually, cannot be combined together to make up one simple proposition, unless all are essential to the subject and none is implied in another.
- Ch. 12. Of propositions affirming or denying the possible, impossible, contingent and necessary, and of their proper contradictories.
- Ch. 13. The relations that subsist between such propositions. The relation of the actual to the possible. Three classes of entities.
- Ch. 14. Of the proper contrary of an affirmation, whether universal or particular.