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All the ideas for 'What is Logic?st1=Ian Hacking', 'Epistemology' and 'Speaking of Objects'

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24 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 / 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 / C. Structure of Existence / 7. Abstract/Concrete / a. Abstract/concrete
1630 We can only see an alien language in terms of our own thought structures (e.g. physical/abstract) [Quine]
7. Existence / D. Theories of Reality / 11. Ontological Commitment / b. Commitment of quantifiers
5747 "No entity without identity" - our ontology must contain items with settled identity conditions [Quine, by Melia]
8. Modes of Existence / B. Properties / 12. Denial of Properties
7925 There is no proper identity concept for properties, and it is hard to distinguish one from two [Quine]
9. Objects / A. Existence of Objects / 2. Abstract Objects / b. Need for abstracta
13387 Our conceptual scheme becomes more powerful when we posit abstract objects [Quine]
9. Objects / A. Existence of Objects / 5. Individuation / a. Individuation
8277 I prefer 'no object without identity' to Quine's 'no entity without identity' [Lowe on Quine]
11. Knowledge Aims / C. Knowing Reality / 2. Phenomenalism
7301 The phenomenalist says that to be is to be perceivable [Cardinal/Hayward/Jones]
7302 Linguistic phenomenalism says we can eliminate talk of physical objects [Cardinal/Hayward/Jones]
7303 If we lack enough sense-data, are we to say that parts of reality are 'indeterminate'? [Cardinal/Hayward/Jones]
12. Knowledge Sources / B. Perception / 2. Qualities in Perception / c. Primary qualities
7299 Primary qualities can be described mathematically, unlike secondary qualities [Cardinal/Hayward/Jones]
7300 An object cannot remain an object without its primary qualities [Cardinal/Hayward/Jones]
13. Knowledge Criteria / B. Internal Justification / 5. Coherentism / c. Coherentism critique
7297 My justifications might be very coherent, but totally unconnected to the world [Cardinal/Hayward/Jones]
19. Language / F. Communication / 6. Interpreting Language / b. Indeterminate translation
1631 You could know the complete behavioural conditions for a foreign language, and still not know their beliefs [Quine]
1632 Translation of our remote past or language could be as problematic as alien languages [Quine]