Combining Texts

All the ideas for 'works', 'Model Theory for Modal Logic I' and 'Fifteen Sermons'

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3 ideas

4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / h. System S5
9560 S5 provides the correct logic for necessity in the broadly logical sense [Fine,K]
     Full Idea: S5 provides the correct logic for necessity in the broadly logical sense.
     From: Kit Fine (Model Theory for Modal Logic I [1978], 151), quoted by Charles Chihara - A Structural Account of Mathematics
     A reaction: I have no view on this, but I am prejudiced in favour of the idea that there is a correct logic for such things, whichever one it may be. Presumably the fact that S5 has no restrictions on accessibility makes it more comprehensive and 'metaphysical'.
5. Theory of Logic / D. Assumptions for Logic / 3. Contradiction
10121 Contradiction is not a sign of falsity, nor lack of contradiction a sign of truth [Pascal]
     Full Idea: Contradiction is not a sign of falsity, nor the lack of contradiction a sign of truth.
     From: Blaise Pascal (works [1660]), quoted by A.George / D.J.Velleman - Philosophies of Mathematics Ch.6
     A reaction: [Quoted in Auden and Kronenberger's Book of Aphorisms] Presumably we would now say that contradiction is a purely formal, syntactic notion, and not a semantic one. If you hit a contradiction, something has certainly gone wrong.
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / c. Ethical intuitionism
8066 Butler exalts conscience, but it may be horribly misleading [Anscombe on Butler]
     Full Idea: Butler exalts conscience, but appears ignorant that a man's conscience may tell him to do the vilest things.
     From: comment on Joseph Butler (Fifteen Sermons [1726]) by G.E.M. Anscombe - Modern Moral Philosophy p.176
     A reaction: That would appear to be the end of conscience. To make conscience work, it must have a huge authority to back it, and also a fairly infallible means of knowing what it truly says, and that an impostor hasn't replaced it (e.g. via a bad upbringing).