Combining Texts

All the ideas for 'fragments/reports', 'Letter to Frege 29.12.1899' and 'Modal Logic within Counterfactual Logic'

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9 ideas

3. Truth / G. Axiomatic Truth / 1. Axiomatic Truth
15716 If axioms and their implications have no contradictions, they pass my criterion of truth and existence [Hilbert]
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / h. System S5
14626 In S5 matters of possibility and necessity are non-contingent [Williamson]
10. Modality / A. Necessity / 1. Types of Modality
14625 Necessity is counterfactually implied by its negation; possibility does not counterfactually imply its negation [Williamson]
10. Modality / B. Possibility / 8. Conditionals / a. Conditionals
14623 Strict conditionals imply counterfactual conditionals: □(A⊃B)⊃(A□→B) [Williamson]
10. Modality / B. Possibility / 9. Counterfactuals
14624 Counterfactual conditionals transmit possibility: (A□→B)⊃(◊A⊃◊B) [Williamson]
10. Modality / C. Sources of Modality / 1. Sources of Necessity
14531 Rather than define counterfactuals using necessity, maybe necessity is a special case of counterfactuals [Williamson, by Hale/Hoffmann,A]
15. Nature of Minds / C. Capacities of Minds / 2. Imagination
14628 Imagination is important, in evaluating possibility and necessity, via counterfactuals [Williamson]
25. Social Practice / E. Policies / 5. Education / b. Education principles
13304 Learned men gain more in one day than others do in a lifetime [Posidonius]
27. Natural Reality / D. Time / 1. Nature of Time / d. Time as measure
20820 Time is an interval of motion, or the measure of speed [Posidonius, by Stobaeus]