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All the ideas for 'What is Logic?st1=Ian Hacking', 'The Roots of Romanticism' and 'A Combinatorial Theory of Possibility'

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19 ideas

1. Philosophy / B. History of Ideas / 5. Later European Thought
7662 Romanticism is the greatest change in the consciousness of the West [Berlin]
2. Reason / D. Definition / 3. Types of Definition
13838 A decent modern definition should always imply a semantics [Hacking]
3. Truth / B. Truthmakers / 6. Making Negative Truths
15547 Negative existentials have 'totality facts' as truthmakers [Armstrong, by Lewis]
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]
10. Modality / B. Possibility / 1. Possibility
15542 All possibilities are recombinations of properties in the actual world [Armstrong, by Lewis]
20. Action / C. Motives for Action / 3. Acting on Reason / b. Intellectualism
7665 Most Enlightenment thinkers believed that virtue consists ultimately in knowledge [Berlin]
23. Ethics / C. Virtue Theory / 3. Virtues / a. Virtues
7676 If we are essentially free wills, authenticity and sincerity are the highest virtues [Berlin]
23. Ethics / D. Deontological Ethics / 2. Duty
7664 The Greeks have no notion of obligation or duty [Berlin]
23. Ethics / F. Existentialism / 1. Existentialism
7677 Central to existentialism is the romantic idea that there is nothing to lean on [Berlin]
29. Religion / B. Monotheistic Religion / 2. Judaism
7663 Judaism and Christianity views are based on paternal, family and tribal relations [Berlin]