The Is-Ought Problem - G. Schurz

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Résumé :
Can OUGHT be derived from IS? This book presents an investigation of this time-honored problem by means of alethic-deontic predicate logic. New in this study is the leitmotif of relevance: is-ought inferences indeed exist, but they are all irrelevant in a precise logical sense. New proof techniques establish this result for very broad classes of logics. A profound philosophical analysis of is-ought bridge principles supplements the logical study. The final results imply incisive limitations for the justifiability of ethics as opposed to empirical science.

Sommaire:
1. Philosophical Background and Program of the Study.- 2. The Logical Background: A.D.1-Logics.- 3. The Logical Explication of Hume's Thesis.- 4. The General Hume Thesis GH.- 5. The Special Hume Thesis SH.- 6. Weakened Versions of Hume's Thesis in A.D.I-Logics with Bridge Principles.- 7. A.D.1-Logics with Weak Alethic Fragments: ? as a Subjective Propositional Attitude.- 8. Generalizations.- 9. Some Applications to Ethical Arguments.- 10. The Problems of Identity and Existence.- 11. Are There Analytic Bridge Principles? A Philosophical Investigation.- 12. Are Synthetic Bridge Principles Scientifically Justifiable?.- A.1 Interchange of substitution for predicates and for individual variables.- A.2 Transitivity of predicate substitutions.- A.5 Preservation of frame-validity under ?-substitution.- A.6 Advancing ?-, a- and d-rule.- A.7 Model-completeness for a.d.l-logics.- A.8 Singleton frames for a.d.1-logics which are not propositionally representable.- A.9 Canonical a.0-logics with incomplete 1-counterparts.- A.10 Canonicity transfer from a.0- to a.1-logics.- A.11 Canonicity transfer from monomodal to combined bimodal 1-logics.- A.12 Halld?ncompleteness and the Bolzano-criterion.- A.13 Correspondence and canonicity for (N1-5).- A.14 Domains of j.1.-models.- A.16 Characterization of a.d.(G)2-logics.- A.17 Admissibility of (?GR).- Table of Definitions, Lemmata, Propositions, Theorems, Corollaries, Facts, Figures and Problems.- Notes.

`... anyone interested in deontic logic should benefit from the insights of this book. ... the work is clearly written and excellently edited.' History and Philosophy of Logic, 19 (1998)