Combining Texts

All the ideas for 'fragments/reports', 'Logical Necessity: Some Issues' and 'Could There Be Unicorns?'

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21 ideas

4. Formal Logic / D. Modal Logic ML / 1. Modal Logic
It was realised that possible worlds covered all modal logics, if they had a structure [Dummett]
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / a. Systems of modal logic
If something is only possible relative to another possibility, the possibility relation is not transitive [Dummett]
Relative possibility one way may be impossible coming back, so it isn't symmetrical [Dummett]
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / d. System T
If possibilitiy is relative, that might make accessibility non-transitive, and T the correct system [Dummett]
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / g. System S4
In S4 the actual world has a special place [Dummett]
10. Modality / A. Necessity / 6. Logical Necessity
Logical necessity overrules all other necessities [McFetridge]
The fundamental case of logical necessity is the valid conclusion of an inference [McFetridge, by Hale]
In the McFetridge view, logical necessity means a consequent must be true if the antecedent is [McFetridge, by Hale]
Logical necessity requires that a valid argument be necessary [McFetridge]
Traditionally, logical necessity is the strongest, and entails any other necessities [McFetridge]
It is only logical necessity if there is absolutely no sense in which it could be false [McFetridge]
The mark of logical necessity is deduction from any suppositions whatever [McFetridge]
10. Modality / B. Possibility / 2. Epistemic possibility
We assert epistemic possibility without commitment to logical possibility [McFetridge]
10. Modality / C. Sources of Modality / 1. Sources of Necessity
Objectual modal realists believe in possible worlds; non-objectual ones rest it on the actual world [McFetridge]
10. Modality / C. Sources of Modality / 5. Modality from Actuality
Modal realists hold that necessities and possibilities are part of the totality of facts [McFetridge]
10. Modality / E. Possible worlds / 1. Possible Worlds / a. Possible worlds
Possible worlds aren't how the world might be, but how a world might be, given some possibility [Dummett]
10. Modality / E. Possible worlds / 1. Possible Worlds / c. Possible worlds realism
If possible worlds have no structure (S5) they are equal, and it is hard to deny them reality [Dummett]
23. Ethics / C. Virtue Theory / 1. Virtue Theory / d. Virtue theory critique
To explain generosity in a person, you must understand a generous action [Dummett]
25. Social Practice / E. Policies / 5. Education / b. Education principles
Learned men gain more in one day than others do in a lifetime [Posidonius]
26. Natural Theory / B. Natural Kinds / 7. Critique of Kinds
Generalised talk of 'natural kinds' is unfortunate, as they vary too much [Dummett]
27. Natural Reality / D. Time / 1. Nature of Time / d. Time as measure
Time is an interval of motion, or the measure of speed [Posidonius, by Stobaeus]