Combining Texts

All the ideas for 'Leibniz', 'A Completeness Theorem in Modal Logic' and 'Defining 'Intrinsic' (with Rae Langton)'

expand these ideas     |    start again     |     specify just one area for these texts


9 ideas

2. Reason / D. Definition / 1. Definitions
Interdefinition is useless by itself, but if we grasp one separately, we have them both [Lewis]
4. Formal Logic / D. Modal Logic ML / 1. Modal Logic
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
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
The variable domain approach to quantified modal logic invalidates the Barcan Formula [Kripke, by Simchen]
The Barcan formulas fail in models with varying domains [Kripke, by Williamson]
8. Modes of Existence / B. Properties / 4. Intrinsic Properties
We must avoid circularity between what is intrinsic and what is natural [Lewis, by Cameron]
A property is 'intrinsic' iff it can never differ between duplicates [Lewis]
Ellipsoidal stars seem to have an intrinsic property which depends on other objects [Lewis]
9. Objects / F. Identity among Objects / 7. Indiscernible Objects
The Identity of Indiscernibles is really the same as the verification principle [Jolley]