Combining Texts

All the ideas for 'fragments/reports', 'In Defense of Absolute Essentialism' and 'Modal Logic'

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17 ideas

4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / b. System K
Normal system K has five axioms and rules [Cresswell]
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / c. System D
D is valid on every serial frame, but not where there are dead ends [Cresswell]
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / g. System S4
S4 has 14 modalities, and always reduces to a maximum of three modal operators [Cresswell]
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / h. System S5
In S5 all the long complex modalities reduce to just three, and their negations [Cresswell]
4. Formal Logic / D. Modal Logic ML / 7. Barcan Formula
Reject the Barcan if quantifiers are confined to worlds, and different things exist in other worlds [Cresswell]
7. Existence / A. Nature of Existence / 3. Being / d. Non-being
Not-Being obviously doesn't exist, and the five modes of Being are all impossible [Gorgias, by Diog. Laertius]
8. Modes of Existence / A. Relations / 4. Formal Relations / a. Types of relation
A relation is 'Euclidean' if aRb and aRc imply bRc [Cresswell]
9. Objects / D. Essence of Objects / 6. Essence as Unifier
A property is essential iff the object would not exist if it lacked that property [Forbes,G]
Properties are trivially essential if they are not grounded in a thing's specific nature [Forbes,G]
9. Objects / D. Essence of Objects / 7. Essence and Necessity / a. Essence as necessary properties
A relation is essential to two items if it holds in every world where they exist [Forbes,G]
9. Objects / D. Essence of Objects / 7. Essence and Necessity / c. Essentials are necessary
Trivially essential properties are existence, self-identity, and de dicto necessities [Forbes,G]
9. Objects / D. Essence of Objects / 9. Essence and Properties
A property is 'extraneously essential' if it is had only because of the properties of other objects [Forbes,G]
9. Objects / D. Essence of Objects / 11. Essence of Artefacts
One might be essentialist about the original bronze from which a statue was made [Forbes,G]
10. Modality / A. Necessity / 4. De re / De dicto modality
A de dicto necessity is true in all worlds, but not necessarily of the same thing in each world [Cresswell]
10. Modality / C. Sources of Modality / 4. Necessity from Concepts
The source of de dicto necessity is not concepts, but the actual properties of the thing [Forbes,G]
19. Language / F. Communication / 1. Rhetoric
Gorgias says rhetoric is the best of arts, because it enslaves without using force [Gorgias, by Plato]
Destroy seriousness with laughter, and laughter with seriousness [Gorgias]