Combining Texts

All the ideas for 'What is Logic?st1=Ian Hacking', 'On Aristotle's Metaphysics Book 2' and 'Concepts:where cogn.science went wrong'

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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]
2. Reason / D. Definition / 13. Against Definition
12619 We have no successful definitions, because they all use indefinable words [Fodor]
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 / A. Nature of Existence / 2. Types of Existence
12620 If 'exist' is ambiguous in 'chairs and numbers exist', that mirrors the difference between chairs and numbers [Fodor]
8. Modes of Existence / C. Powers and Dispositions / 6. Dispositions / c. Dispositions as conditional
12613 Empiricists use dispositions reductively, as 'possibility of sensation' or 'possibility of experimental result' [Fodor]
12. Knowledge Sources / D. Empiricism / 2. Associationism
12617 Associationism can't explain how truth is preserved [Fodor]
18. Thought / C. Content / 2. Ideas
12615 Mental representations are the old 'Ideas', but without images [Fodor]
18. Thought / D. Concepts / 2. Origin of Concepts / c. Nativist concepts
6650 Fodor is now less keen on the innateness of concepts [Fodor, by Lowe]
18. Thought / D. Concepts / 3. Ontology of Concepts / a. Concepts as representations
12618 It is essential to the concept CAT that it be satisfied by cats [Fodor]
18. Thought / D. Concepts / 3. Ontology of Concepts / b. Concepts as abilities
12614 I prefer psychological atomism - that concepts are independent of epistemic capacities [Fodor]
18. Thought / D. Concepts / 4. Structure of Concepts / b. Analysis of concepts
12621 Definable concepts have constituents, which are necessary, individuate them, and demonstrate possession [Fodor]
18. Thought / D. Concepts / 4. Structure of Concepts / d. Concepts as prototypes
12622 Many concepts lack prototypes, and complex prototypes aren't built from simple ones [Fodor]
18. Thought / D. Concepts / 4. Structure of Concepts / f. Theory theory of concepts
12623 The theory theory can't actually tell us what concepts are [Fodor]
19. Language / C. Assigning Meanings / 2. Semantics
12616 English has no semantic theory, just associations between sentences and thoughts [Fodor]
26. Natural Theory / A. Speculations on Nature / 6. Early Matter Theories / g. Atomism
20919 How can things without weight compose weight? [Alexander]