Combining Texts

All the ideas for 'works', 'Model Theory for Modal Logic I' and 'Knowledge by Acquaintance and Description-1'

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4 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.
8. Modes of Existence / D. Universals / 2. Need for Universals
21710 We know a universal in 'yellow differs from blue' or 'yellow resembles blue less than green does' [Russell]
     Full Idea: We are aware of the universal 'yellow'; this universal is the subject in such judgements as 'yellow differs from blue' or 'yellow resembles blue less than green does'.
     From: Bertrand Russell (Knowledge by Acquaintance and Description-1 [1911], 154), quoted by Bernard Linsky - Russell's Metaphysical Logic 2.3
     A reaction: This still seems one of the strongest examples in support of universals. You could hardly be talking about yellow tropes in such instances (even if the world does contain yellow tropes).
12. Knowledge Sources / B. Perception / 4. Sense Data / d. Sense-data problems
8854 My 'acquaintance' with sense-data is nothing like my knowing New York [Williams,M on Russell]
     Full Idea: My 'acquaintance' with sense-data is nothing like my knowing New York.
     From: comment on Bertrand Russell (Knowledge by Acquaintance and Description-1 [1911]) by Michael Williams - Without Immediate Justification §4
     A reaction: This pinpoints a nice difficulty for Russell. Williams may misrepresent Russell's account of acquaintance, but that is probably because Russell is unclear, or uncertain. The problem is when Russell claims that his acquaintance gives knowledge.