Combining Texts

All the ideas for 'fragments/reports', 'Counterfactuals' and 'A Completeness Theorem in Modal Logic'

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10 ideas

4. Formal Logic / D. Modal Logic ML / 1. Modal Logic

10163

Propositional modal logic has been proved to be complete [Kripke, by Feferman/Feferman]

4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / a. Systems of modal logic

10760

With possible worlds, S4 and S5 are sound and complete, but S1-S3 are not even sound [Kripke, by Rossberg]

4. Formal Logic / D. Modal Logic ML / 7. Barcan Formula

16189

The variable domain approach to quantified modal logic invalidates the Barcan Formula [Kripke, by Simchen]

15132

The Barcan formulas fail in models with varying domains [Kripke, by Williamson]

7. Existence / A. Nature of Existence / 3. Being / d. Non-being

18933

Not-Being obviously doesn't exist, and the five modes of Being are all impossible [Gorgias, by Diog. Laertius]

10. Modality / B. Possibility / 8. Conditionals / c. Truth-function conditionals

14361

Lewis says indicative conditionals are truth-functional [Lewis, by Jackson]

10. Modality / B. Possibility / 9. Counterfactuals

8434	In good counterfactuals the consequent holds in world like ours except that the antecedent is true [Lewis, by Horwich]

19. Language / F. Communication / 1. Rhetoric

9866	Gorgias says rhetoric is the best of arts, because it enslaves without using force [Gorgias, by Plato]

5864	Destroy seriousness with laughter, and laughter with seriousness [Gorgias]

26. Natural Theory / D. Laws of Nature / 4. Regularities / b. Best system theory

9419	A law of nature is a general axiom of the deductive system that is best for simplicity and strength [Lewis]