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All the ideas for 'What is Logic?st1=Ian Hacking', 'Review: Meinong 'Untersuchungen zur..'' and 'Identity and Necessity'

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22 ideas

1. Philosophy / F. Analytic Philosophy / 6. Logical Analysis
21546 We can't sharply distinguish variables, domains and values, if symbols frighten us [Russell]
2. Reason / D. Definition / 3. Types of Definition
13838 A decent modern definition should always imply a semantics [Hacking]
4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / d. Basic theorems of PL
13834 Gentzen's Cut Rule (or transitivity of deduction) is 'If A |- B and B |- C, then A |- C' [Hacking]
13835 Only Cut reduces complexity, so logic is constructive without it, and it can be dispensed with [Hacking]
13833 'Thinning' ('dilution') is the key difference between deduction (which allows it) and induction [Hacking]
5. Theory of Logic / A. Overview of Logic / 4. Pure Logic
13845 The various logics are abstractions made from terms like 'if...then' in English [Hacking]
5. Theory of Logic / A. Overview of Logic / 5. First-Order Logic
13840 First-order logic is the strongest complete compact theory with Löwenheim-Skolem [Hacking]
13844 A limitation of first-order logic is that it cannot handle branching quantifiers [Hacking]
5. Theory of Logic / A. Overview of Logic / 7. Second-Order Logic
13842 Second-order completeness seems to need intensional entities and possible worlds [Hacking]
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / a. Logical connectives
13837 With a pure notion of truth and consequence, the meanings of connectives are fixed syntactically [Hacking]
5. Theory of Logic / E. Structures of Logic / 4. Variables in Logic
13839 Perhaps variables could be dispensed with, by arrows joining places in the scope of quantifiers [Hacking]
5. Theory of Logic / F. Referring in Logic / 1. Naming / b. Names as descriptive
9175 We may fix the reference of 'Cicero' by a description, but thereafter the name is rigid [Kripke]
5. Theory of Logic / F. Referring in Logic / 1. Naming / c. Names as referential
9171 The function of names is simply to refer [Kripke]
5. Theory of Logic / J. Model Theory in Logic / 3. Löwenheim-Skolem Theorems
13843 If it is a logic, the Löwenheim-Skolem theorem holds for it [Hacking]
9. Objects / A. Existence of Objects / 4. Impossible objects
21531 Common sense agrees with Meinong (rather than Russell) that 'Pegasus is a flying horse' is true [Lackey on Russell]
21545 I prefer to deny round squares, and deal with the difficulties by the theory of denoting [Russell]
10. Modality / D. Knowledge of Modality / 3. A Posteriori Necessary
9174 It is necessary that this table is not made of ice, but we don't know it a priori [Kripke]
10. Modality / E. Possible worlds / 3. Transworld Objects / b. Rigid designation
9172 A 'rigid designator' designates the same object in all possible worlds [Kripke]
9173 We cannot say that Nixon might have been a different man from the one he actually was [Kripke]
10. Modality / E. Possible worlds / 3. Transworld Objects / c. Counterparts
9176 Modal statements about this table never refer to counterparts; that confuses epistemology and metaphysics [Kripke]
17. Mind and Body / A. Mind-Body Dualism / 7. Zombies
9177 Identity theorists must deny that pains can be imagined without brain states [Kripke]
17. Mind and Body / E. Mind as Physical / 7. Anti-Physicalism / e. Modal argument
9178 Pain, unlike heat, is picked out by an essential property [Kripke]