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All the ideas for 'What is Logic?st1=Ian Hacking', 'Artistic Value and Opportunistic Moralism' and 'The Relation of Sense-Data to Physics'

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33 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
'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]
7. Existence / C. Structure of Existence / 8. Stuff / a. Pure stuff
Continuity is a sufficient criterion for the identity of a rock, but not for part of a smooth fluid [Russell]
9. Objects / A. Existence of Objects / 1. Physical Objects
Physical things are series of appearances whose matter obeys physical laws [Russell]
9. Objects / B. Unity of Objects / 2. Substance / e. Substance critique
We need not deny substance, but there seems no reason to assert it [Russell]
The assumption by physicists of permanent substance is not metaphysically legitimate [Russell]
11. Knowledge Aims / C. Knowing Reality / 2. Phenomenalism
Where possible, logical constructions are to be substituted for inferred entities [Russell]
12. Knowledge Sources / B. Perception / 4. Sense Data / b. Nature of sense-data
No sensibile is ever a datum to two people at once [Russell]
Russell held that we are aware of states of our own brain [Russell, by Robinson,H]
Sense-data are qualities devoid of subjectivity, which are the basis of science [Russell, by Deleuze/Guattari]
Sense-data are not mental, but are part of the subject-matter of physics [Russell]
Sense-data are objects, and do not contain the subject as part, the way beliefs do [Russell]
Sense-data are usually objects within the body, but are not part of the subject [Russell]
12. Knowledge Sources / B. Perception / 4. Sense Data / c. Unperceived sense-data
We do not know whether sense-data exist as objects when they are not data [Russell]
'Sensibilia' are identical to sense-data, without actually being data for any mind [Russell]
Ungiven sense-data can no more exist than unmarried husbands [Russell]
12. Knowledge Sources / B. Perception / 4. Sense Data / d. Sense-data problems
Individuating sense-data is difficult, because they divide when closely attended to [Russell]
Sense-data may be subjective, if closing our eyes can change them [Russell]
21. Aesthetics / C. Artistic Issues / 7. Art and Morality
The works we value most are in sympathy with our own moral views [John,E]
We should understand what is morally important in a story, without having to endorse it [John,E]
We value morality in art because that is what we care about - but it is a contingent fact [John,E]
A work can be morally and artistically excellent, despite rejecting moral truth [John,E]
27. Natural Reality / B. Modern Physics / 4. Standard Model / a. Concept of matter
Matter is the limit of appearances as distance from the object diminishes [Russell]
27. Natural Reality / C. Space / 2. Space
There is 'private space', and there is also the 'space of perspectives' [Russell]