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All the ideas for 'What is Logic?st1=Ian Hacking', 'The Common-Sense View of Reality' and 'works'

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18 ideas

1. Philosophy / E. Nature of Metaphysics / 2. Possibility of Metaphysics
20728 Metaphysics is hopeless with its present epistemology; common-sense realism is needed [Colvin]
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 / J. Model Theory in Logic / 3. Löwenheim-Skolem Theorems
13843 If it is a logic, the Löwenheim-Skolem theorem holds for it [Hacking]
7. Existence / D. Theories of Reality / 2. Realism
20726 We can only distinguish self from non-self if there is an inflexible external reality [Colvin]
20727 Common-sense realism rests on our interests and practical life [Colvin]
7. Existence / D. Theories of Reality / 4. Anti-realism
20730 If objects are doubted because their appearances change, that presupposes one object [Colvin]
20729 Arguments that objects are unknowable or non-existent assume the knower's existence [Colvin]
20731 The idea that everything is relations is contradictory; relations are part of the concept of things [Colvin]
13. Knowledge Criteria / B. Internal Justification / 3. Evidentialism / b. Evidentialism
6587 It is always wrong to believe things on insufficient evidence [Clifford]