Combining Texts

All the ideas for 'What is Logic?st1=Ian Hacking', 'On Assertion and Indicative Conditionals' and 'Capitalism and Community'

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18 ideas

2. Reason / D. Definition / 3. Types of Definition
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
'Thinning' ('dilution') is the key difference between deduction (which allows it) and induction [Hacking]
Gentzen's Cut Rule (or transitivity of deduction) is 'If A |- B and B |- C, then A |- C' [Hacking]
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 / 4. Pure Logic
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
First-order logic is the strongest complete compact theory with Löwenheim-Skolem [Hacking]
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
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
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
Perhaps variables could be dispensed with, by arrows joining places in the scope of quantifiers [Hacking]
5. Theory of Logic / J. Model Theory in Logic / 3. Löwenheim-Skolem Theorems
If it is a logic, the Löwenheim-Skolem theorem holds for it [Hacking]
10. Modality / B. Possibility / 8. Conditionals / c. Truth-function conditionals
'If A,B' affirms that A⊃B, and also that this wouldn't change if A were certain [Jackson, by Edgington]
Conditionals are truth-functional, but should only be asserted when they are confident [Jackson, by Edgington]
24. Political Theory / D. Ideologies / 11. Capitalism
Capitalism may actually be the best way to foster community [Conway,D]
Capitalism is just the market, with optional limited government, and perhaps democracy [Conway,D]
Capitalism prefers representative democracy, which avoids community decision-making [Conway,D]
Capitalism breaks up extended families, and must then provide welfare for the lonely people [Conway,D]
Capitalism is anti-community, by only valuing individuals, and breaking up families [Conway,D]