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All the ideas for 'What is Logic?st1=Ian Hacking', 'On the Nature of Moral Values' and 'Essence, Necessity and Explanation'

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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 / 4. Real Definition
15118 A successful Aristotelian 'definition' is what sciences produces after an investigation [Koslicki]
2. Reason / D. Definition / 6. Definition by Essence
15116 Essences cause necessary features, and definitions describe those necessary features [Koslicki]
3. Truth / C. Correspondence Truth / 1. Correspondence Truth
21750 Science is sympathetic to truth as correspondence, since it depends on observation [Quine]
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 / 1. Essences of Objects
15110 An essence and what merely follow from it are distinct [Koslicki]
9. Objects / D. Essence of Objects / 3. Individual Essences
15113 Individuals are perceived, but demonstration and definition require universals [Koslicki]
9. Objects / D. Essence of Objects / 7. Essence and Necessity / c. Essentials are necessary
15112 If an object exists, then its essential properties are necessary [Koslicki]
14. Science / A. Basis of Science / 2. Demonstration
15111 In demonstration, the explanatory order must mirror the causal order of the phenomena [Koslicki]
15115 In a demonstration the middle term explains, by being part of the definition [Koslicki]
14. Science / C. Induction / 2. Aims of Induction
21748 More careful inductions gradually lead to the hypothetico-deductive method [Quine]
14. Science / D. Explanation / 2. Types of Explanation / g. Causal explanations
15117 Greek uses the same word for 'cause' and 'explanation' [Koslicki]
14. Science / D. Explanation / 2. Types of Explanation / k. Explanations by essence
15114 Discovering the Aristotelian essence of thunder will tell us why thunder occurs [Koslicki]
22. Metaethics / B. Value / 1. Nature of Value / a. Nature of value
21749 Altruistic values concern other persons, and ceremonial values concern practices [Quine]
22. Metaethics / B. Value / 2. Values / g. Love
21751 Love seems to diminish with distance from oneself [Quine]