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All the ideas for 'What is Logic?st1=Ian Hacking', 'The Dappled World' and 'Principle Doctrines ('Kuriai Doxai') (frags)'

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23 ideas

1. Philosophy / A. Wisdom / 2. Wise People
14519 It is a great good to show reverence for a wise man [Epicurus]
1. Philosophy / D. Nature of Philosophy / 2. Invocation to Philosophy
14518 In the study of philosophy, pleasure and knowledge arrive simultaneously [Epicurus]
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]
9. Objects / A. Existence of Objects / 5. Individuation / b. Individuation by properties
14524 Bodies are combinations of shape, size, resistance and weight [Epicurus]
14. Science / B. Scientific Theories / 1. Scientific Theory
17503 Theories can never represent accurately, because their components are abstract [Cartwright,N, by Portides]
16. Persons / F. Free Will / 6. Determinism / a. Determinism
14521 If everything is by necessity, then even denials of necessity are by necessity [Epicurus]
22. Metaethics / C. The Good / 2. Happiness / c. Value of happiness
14522 What happens to me if I obtain all my desires, and what if I fail? [Epicurus]
22. Metaethics / C. The Good / 3. Pleasure / e. Role of pleasure
3563 Pleasure and virtue entail one another [Epicurus]
23. Ethics / B. Contract Ethics / 1. Contractarianism
3560 Justice is merely a contract about not harming or being harmed [Epicurus]
23. Ethics / C. Virtue Theory / 2. Elements of Virtue Theory / e. Character
14517 We value our own character, whatever it is, and we should respect the characters of others [Epicurus]
23. Ethics / C. Virtue Theory / 3. Virtues / c. Justice
14513 Justice is a pledge of mutual protection [Epicurus]
24. Political Theory / B. Nature of a State / 2. State Legitimacy / c. Social contract
14515 A law is not just if it is not useful in mutual associations [Epicurus]
25. Social Practice / F. Life Issues / 4. Suicide
14520 It is small-minded to find many good reasons for suicide [Epicurus]