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All the ideas for 'What is Logic?st1=Ian Hacking', 'Quodlibeta' and 'Truth-makers'

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21 ideas

2. Reason / D. Definition / 3. Types of Definition
13838 A decent modern definition should always imply a semantics [Hacking]
3. Truth / B. Truthmakers / 2. Truthmaker Relation
10911 Part-whole is the key relation among truth-makers [Mulligan/Simons/Smith]
3. Truth / B. Truthmakers / 5. What Makes Truths / a. What makes truths
10909 Truth-makers cannot be the designata of the sentences they make true [Mulligan/Simons/Smith]
10906 Moments (objects which cannot exist alone) may serve as truth-makers [Mulligan/Simons/Smith]
10907 The truth-maker for a sentence may not be unique, or may be a combination, or several separate items [Mulligan/Simons/Smith]
10912 Despite negative propositions, truthmakers are not logical complexes, but ordinary experiences [Mulligan/Simons/Smith]
3. Truth / C. Correspondence Truth / 3. Correspondence Truth critique
10908 Correspondence has to invoke facts or states of affairs, just to serve as truth-makers [Mulligan/Simons/Smith]
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 / E. Categories / 3. Proposed Categories
16657 Substance, Quantity and Quality are real; other categories depend on those three [Henry of Ghent]
8. Modes of Existence / A. Relations / 1. Nature of Relations
16658 The only reality in the category of Relation is things from another category [Henry of Ghent]
8. Modes of Existence / B. Properties / 8. Properties as Modes
16645 Accidents are diminished beings, because they are dispositions of substance (unqualified being) [Henry of Ghent]
11. Knowledge Aims / C. Knowing Reality / 3. Idealism / b. Transcendental idealism
22012 Kant says things-in-themselves cause sensations, but then makes causation transcendental! [Henry of Ghent, by Pinkard]