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All the ideas for 'What is Logic?st1=Ian Hacking', 'works' and 'The Coherence Theory of Truth'

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25 ideas

2. Reason / B. Laws of Thought / 6. Ockham's Razor
Do not multiply entities beyond necessity [William of Ockham]
2. Reason / D. Definition / 3. Types of Definition
A decent modern definition should always imply a semantics [Hacking]
3. Truth / B. Truthmakers / 12. Rejecting Truthmakers
For idealists reality is like a collection of beliefs, so truths and truthmakers are not distinct [Young,JO]
3. Truth / D. Coherence Truth / 1. Coherence Truth
Coherence theories differ over the coherence relation, and over the set of proposition with which to cohere [Young,JO]
Two propositions could be consistent with your set, but inconsistent with one another [Young,JO]
Coherence with actual beliefs, or our best beliefs, or ultimate ideal beliefs? [Young,JO]
Coherent truth is not with an arbitrary set of beliefs, but with a set which people actually do believe [Young,JO]
3. Truth / D. Coherence Truth / 2. Coherence Truth Critique
How do you identify the best coherence set; and aren't there truths which don't cohere? [Young,JO]
3. Truth / H. Deflationary Truth / 2. Deflationary Truth
Deflationary theories reject analysis of truth in terms of truth-conditions [Young,JO]
4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / d. Basic theorems of PL
'Thinning' ('dilution') is the key difference between deduction (which allows it) and induction [Hacking]
Gentzen's Cut Rule (or transitivity of deduction) is 'If A |- B and B |- C, then A |- C' [Hacking]
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
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
First-order logic is the strongest complete compact theory with Löwenheim-Skolem [Hacking]
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
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
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
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
If it is a logic, the Löwenheim-Skolem theorem holds for it [Hacking]
8. Modes of Existence / D. Universals / 5. Universals as Concepts
Species and genera are individual concepts which naturally signify many individuals [William of Ockham]
19. Language / A. Nature of Meaning / 4. Meaning as Truth-Conditions
Are truth-condtions other propositions (coherence) or features of the world (correspondence)? [Young,JO]
Coherence truth suggests truth-condtions are assertion-conditions, which need knowledge of justification [Young,JO]
27. Natural Reality / D. Time / 1. Nature of Time / i. Denying time
The past has ceased to exist, and the future does not yet exist, so time does not exist [William of Ockham]
28. God / A. Divine Nature / 6. Divine Morality / d. God decrees morality
William of Ockham is the main spokesman for God's commands being the source of morality [William of Ockham]
29. Religion / B. Monotheistic Religion / 4. Christianity / c. Angels
Even an angel must have some location [William of Ockham, by Pasnau]