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All the ideas for 'Reply to Richards', 'Postscripts on supervenience' and 'An Introduction to Modal Logic'

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7 ideas

1. Philosophy / E. Nature of Metaphysics / 3. Metaphysical Systems
The greatest philosophers are methodical; it is what makes them great [Grice]
     Full Idea: The greatest philosophers have been the greatest, and most self-conscious, methodologists; indeed, I am tempted to regard the fact as primarily accounting for their greatness as philosophers.
     From: H. Paul Grice (Reply to Richards [1986], p.66), quoted by Stephen Boulter - Why Medieval Philosophy Matters 3
     A reaction: I agree. Philosophy is nothing if it is not devoted to the attempt to be fully rational, and that implies consistency and coherence. If a thinker doesn't even try to be systematic, I would not consider them to be a philosopher.
4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / b. Terminology of PL
A 'value-assignment' (V) is when to each variable in the set V assigns either the value 1 or the value 0 [Hughes/Cresswell]
     Full Idea: A 'value-assignment' (V) is when to each variable in the set V assigns either the value 1 or the value 0.
     From: GE Hughes/M Cresswell (An Introduction to Modal Logic [1968], Ch.1)
     A reaction: In the interpreted version of the logic, 1 and 0 would become T (true) and F (false). The procedure seems to be called nowadays a 'valuation'.
4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / d. Basic theorems of PL
The Law of Transposition says (P→Q) → (¬Q→¬P) [Hughes/Cresswell]
     Full Idea: The Law of Transposition says that (P→Q) → (¬Q→¬P).
     From: GE Hughes/M Cresswell (An Introduction to Modal Logic [1968], Ch.1)
     A reaction: That is, if the consequent (Q) of a conditional is false, then the antecedent (P) must have been false.
4. Formal Logic / B. Propositional Logic PL / 4. Soundness of PL
The rules preserve validity from the axioms, so no thesis negates any other thesis [Hughes/Cresswell]
     Full Idea: An axiomatic system is most naturally consistent iff no thesis is the negation of another thesis. It can be shown that every axiom is valid, that the transformation rules are validity-preserving, and if a wff α is valid, then ¬α is not valid.
     From: GE Hughes/M Cresswell (An Introduction to Modal Logic [1968], Ch.1)
     A reaction: [The labels 'soundness' and 'consistency' seem interchangeable here, with the former nowadays preferred]
5. Theory of Logic / K. Features of Logics / 4. Completeness
A system is 'weakly' complete if all wffs are derivable, and 'strongly' if theses are maximised [Hughes/Cresswell]
     Full Idea: To say that an axiom system is 'weakly complete' is to say that every valid wff of the system is derivable as a thesis. ..The system is 'strongly complete' if it cannot have any more theses than it has without falling into inconsistency.
     From: GE Hughes/M Cresswell (An Introduction to Modal Logic [1968], Ch.1)
     A reaction: [They go on to say that Propositional Logic is strongly complete, but Modal Logic is not]
7. Existence / C. Structure of Existence / 5. Supervenience / c. Significance of supervenience
Supervenience is not a dependence relation, on the lines of causal, mereological or semantic dependence [Kim]
     Full Idea: It is a mistake, or at least misleading, to think of supervenience itself as a special and distinctive type of dependence relation, alongside causal dependence, mereological dependence, semantic dependence, and others.
     From: Jaegwon Kim (Postscripts on supervenience [1993], 2)
     A reaction: The point, I take it, is that supervenience is something which requires explanation, rather than being a conclusion to the debate. Why are statues beautiful? Why do brains generate minds?
Supervenience is just a 'surface' relation of pattern covariation, which still needs deeper explanation [Kim]
     Full Idea: Supervenience itself is not an explanatory relation, not a 'deep' metaphysical relation; rather it is a 'surface' relation that reports a pattern of property covariation, suggesting the presence of an interesting dependency relation that might explain it.
     From: Jaegwon Kim (Postscripts on supervenience [1993], 2)
     A reaction: I think the underlying idea here is that supervenience appeals to the Humean view of physical laws as mere regularities, but it is no good for those who seek underlying mechanisms to explain the patterns and regularities. Humeans are wrong.