9.1 Identity translations -- 9.2 Identity proofs -- 9.3 Easier relations -- 9.4 Harder relations -- 9.5 Relational proofs -- 9.6 Definite descriptions -- 9.7 Copi proofs -- 10 Basic Modal Logic -- 10.1 Translations -- 10.2 Proofs -- 10.3 Refutations -- 11 Further Modal Systems -- 11.1 Galactic travel -- 11.2 Quantified translations -- 11.3 Quantified proofs -- 11.4 A sophisticated system -- 12 Deontic and Imperative Logic -- 12.1 Imperative translations -- 12.2 Imperative proofs -- 12.3 Deontic translations -- 12.4 Deontic proofs -- 13 Belief Logic -- 13.1 Belief translations -- 13.2 Belief proofs -- 13.3 Believing and willing -- 13.4 Willing proofs -- 13.5 Rationality translations -- 13.6 Rationality proofs -- 13.7 A sophisticated system -- 14 A Formalized Ethical Theory -- 14.1 Practical reason -- 14.2 Consistency -- 14.3 The golden rule -- 14.4 Starting the GR proof -- 14.5 GR logical machinery -- 14.6 The symbolic GR proof -- 15 Metalogic -- 15.1 Metalogical questions -- 15.2 Symbols -- 15.3 Soundness -- 15.4 Completeness -- 15.5 An axiomatic system -- 15.6 Gödel's theorem -- 16 History of Logic -- 16.1 Ancient logic -- 16.2 Medieval logic -- 16.3 Enlightenment logic -- 16.4 Frege and Russell -- 16.5 After Principia -- 17 Deviant Logics -- 17.1 Many-valued logic -- 17.2 Paraconsistent logic -- 17.3 Intuitionist logic -- 17.4 Relevance logic -- 18 Philosophy of Logic -- 18.1 Abstract entities -- 18.2 Metaphysical structures -- 18.3 The basis for logical laws -- 18.4 Truth and paradoxes -- 18.5 Logic's scope -- For Further Reading -- Answers to Selected Problems -- Chapter 2 answers -- Chapter 3 answers -- Chapter 4 answers -- Chapter 5 answers -- Chapter 6 answers -- Chapter 7 answers -- Chapter 8 answers -- Chapter 9 answers -- Chapter 10 answers -- Chapter 11 answers -- Chapter 12 answers -- Chapter 13 answers -- Chapter 14 answers -- Index