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All the ideas for 'What is Logic?st1=Ian Hacking', 'Meaning and Necessity' and 'Pref to new 'Materialist Theory''

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20 ideas

2. Reason / D. Definition / 3. Types of Definition
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
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]
12. Knowledge Sources / B. Perception / 2. Qualities in Perception / d. Secondary qualities
Secondary qualities are microscopic primary qualities of physical things [Armstrong]
15. Nature of Minds / B. Features of Minds / 1. Consciousness / b. Essence of consciousness
Consciousness and experience of qualities are not the same [Armstrong]
17. Mind and Body / B. Behaviourism / 1. Behaviourism
Behaviourism is false, but mind is definable as the cause of behaviour [Armstrong]
17. Mind and Body / B. Behaviourism / 2. Potential Behaviour
The manifestations of a disposition need never actually exist [Armstrong]
17. Mind and Body / C. Functionalism / 4. Causal Functionalism
Causal Functionalism says mental states are apt for producing behaviour [Armstrong]
17. Mind and Body / C. Functionalism / 5. Teleological Functionalism
A causal theory of mentality would be improved by a teleological element [Armstrong]
17. Mind and Body / E. Mind as Physical / 1. Physical Mind
The identity of mental states with physical properties is contingent, because the laws of nature are contingent [Armstrong]
17. Mind and Body / E. Mind as Physical / 7. Anti-Physicalism / b. Multiple realisability
One mental role might be filled by a variety of physical types [Armstrong]
19. Language / C. Assigning Meanings / 8. Possible Worlds Semantics
The intension of a sentence is the set of all possible worlds in which it is true [Carnap, by Kaplan]