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All the ideas for 'What is Logic?st1=Ian Hacking', 'Substance and Essence in Aristotle' and 'Causality and Explanation'

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18 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
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]
9. Objects / D. Essence of Objects / 2. Types of Essence
12066 Aristotelian and Kripkean essentialism are very different theories [Witt]
9. Objects / D. Essence of Objects / 4. Essence as Definition
12067 An Aristotelian essence is a nonlinguistic correlate of the definition [Witt]
9. Objects / D. Essence of Objects / 6. Essence as Unifier
12082 If unity is a matter of degree, then essence may also be a matter of degree [Witt]
9. Objects / D. Essence of Objects / 8. Essence as Explanatory
12089 Essences mainly explain the existence of unified substance [Witt]
9. Objects / E. Objects over Time / 12. Origin as Essential
12102 Essential properties of origin are too radically individual for an Aristotelian essence [Witt]
14. Science / D. Explanation / 2. Types of Explanation / i. Explanations by mechanism
16557 Salmon's mechanisms are processes and interactions, involving marks, or conserved quantities [Salmon, by Machamer/Darden/Craver]
26. Natural Theory / D. Laws of Nature / 8. Scientific Essentialism / a. Scientific essentialism
12085 Reality is directional [Witt]