Combining Texts

All the ideas for 'Explaining the A Priori', 'What is Logic?' and 'Philosophy and the Nature of Language'

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25 ideas

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 / F. Referring in Logic / 2. Descriptions / c. Theory of definite descriptions
4568 If 'Queen of England' does not refer if there is no queen, its meaning can't refer if there is one [Cooper,DE]
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 / 5. Category Anti-Realism
4574 If some peoples do not have categories like time or cause, they can't be essential features of rationality [Cooper,DE]
13. Knowledge Criteria / E. Relativism / 5. Language Relativism
4573 If it is claimed that language correlates with culture, we must be able to identify the two independently [Cooper,DE]
4575 A person's language doesn't prove their concepts, but how are concepts deduced apart from language? [Cooper,DE]
17. Mind and Body / B. Behaviourism / 2. Potential Behaviour
4561 Many sentences set up dispositions which are irrelevant to the meanings of the sentences [Cooper,DE]
18. Thought / D. Concepts / 2. Origin of Concepts / a. Origin of concepts
17722 The concept 'red' is tied to what actually individuates red things [Peacocke]
19. Language / A. Nature of Meaning / 5. Meaning as Verification
4564 I can meaningfully speculate that humans may have experiences currently impossible for us [Cooper,DE]
4565 The verification principle itself seems neither analytic nor verifiable [Cooper,DE]
19. Language / A. Nature of Meaning / 6. Meaning as Use
4563 'How now brown cow?' is used for elocution, but this says nothing about its meaning [Cooper,DE]
4562 Most people know how to use the word "Amen", but they do not know what it means [Cooper,DE]
19. Language / B. Reference / 1. Reference theories
4571 Reference need not be a hit-or-miss affair [Cooper,DE]
4566 Any thesis about reference is also a thesis about what exists to be referred to [Cooper,DE]
19. Language / C. Assigning Meanings / 3. Predicates
4572 If predicates name things, that reduces every sentence to a mere list of names [Cooper,DE]
19. Language / E. Analyticity / 2. Analytic Truths
4576 An analytic truth is one which becomes a logical truth when some synonyms have been replaced [Cooper,DE]