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All the ideas for 'What is Logic?st1=Ian Hacking', 'Reference and Definite Descriptions' and 'The Logic of Boundaryless Concepts'

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21 ideas

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
13833 'Thinning' ('dilution') is the key difference between deduction (which allows it) and induction [Hacking]
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]
5. Theory of Logic / A. Overview of Logic / 3. Value of Logic
9390 Logic guides thinking, but it isn't a substitute for it [Rumfitt]
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 / 2. Descriptions / a. Descriptions
7760 Russell only uses descriptions attributively, and Strawson only referentially [Donnellan, by Lycan]
5. Theory of Logic / F. Referring in Logic / 2. Descriptions / b. Definite descriptions
5811 A definite description can have a non-referential use [Donnellan]
5812 Definite descriptions are 'attributive' if they say something about x, and 'referential' if they pick x out [Donnellan]
5814 'The x is F' only presumes that x exists; it does not actually entail the existence [Donnellan]
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 / B. Unity of Objects / 3. Unity Problems / e. Vague objects
9389 Vague membership of sets is possible if the set is defined by its concept, not its members [Rumfitt]
19. Language / B. Reference / 4. Descriptive Reference / b. Reference by description
10435 A definite description 'the F' is referential if the speaker could thereby be referring to something not-F [Donnellan, by Sainsbury]
10451 Donnellan is unclear whether the referential-attributive distinction is semantic or pragmatic [Bach on Donnellan]
5813 A description can successfully refer, even if its application to the subject is not believed [Donnellan]
19. Language / B. Reference / 5. Speaker's Reference
5815 Whether a definite description is referential or attributive depends on the speaker's intention [Donnellan]