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All the ideas for 'What is Logic?st1=Ian Hacking', 'A Defense of Presentism' and 'Does Emp.Knowledge have Foundation?'

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27 ideas

1. Philosophy / G. Scientific Philosophy / 3. Scientism
People who use science to make philosophical points don't realise how philosophical science is [Markosian]
2. Reason / D. Definition / 3. Types of Definition
A decent modern definition should always imply a semantics [Hacking]
3. Truth / B. Truthmakers / 9. Making Past Truths
Presentism has the problem that if Socrates ceases to exist, so do propositions about him [Markosian]
4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / d. Basic theorems of PL
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]
'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
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]
10. Modality / E. Possible worlds / 2. Nature of Possible Worlds / a. Nature of possible worlds
Possible worlds must be abstract, because two qualitatively identical worlds are just one world [Markosian]
13. Knowledge Criteria / B. Internal Justification / 4. Foundationalism / c. Empirical foundations
If observation is knowledge, it is not just an experience; it is a justification in the space of reasons [Sellars]
13. Knowledge Criteria / B. Internal Justification / 4. Foundationalism / f. Foundationalism critique
Observations like 'this is green' presuppose truths about what is a reliable symptom of what [Sellars]
18. Thought / D. Concepts / 4. Structure of Concepts / f. Theory theory of concepts
The concept of 'green' involves a battery of other concepts [Sellars]
19. Language / A. Nature of Meaning / 4. Meaning as Truth-Conditions
'Grabby' truth conditions first select their object, unlike 'searchy' truth conditions [Markosian]
27. Natural Reality / D. Time / 1. Nature of Time / h. Presentism
Presentism is the view that only present objects exist [Markosian]
Presentism says if objects don't exist now, we can't have attitudes to them or relations with them [Markosian]
Presentism seems to entail that we cannot talk about other times [Markosian]
Serious Presentism says things must exist to have relations and properties; Unrestricted version denies this [Markosian]
Maybe Presentists can refer to the haecceity of a thing, after the thing itself disappears [Markosian]
Maybe Presentists can paraphrase singular propositions about the past [Markosian]
Special Relativity denies the absolute present which Presentism needs [Markosian]
27. Natural Reality / D. Time / 2. Passage of Time / k. Temporal truths
Objects in the past, like Socrates, are more like imaginary objects than like remote spatial objects [Markosian]
People are mistaken when they think 'Socrates was a philosopher' says something [Markosian]