Combining Texts

All the ideas for 'What is Logic?st1=Ian Hacking', 'Croce and Collingwood' and 'Causation and the Manifestation of Powers'

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18 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]
15. Nature of Minds / C. Capacities of Minds / 9. Perceiving Causation
Causation seems to be an innate concept (or acquired very early) [Bird]
21. Aesthetics / A. Aesthetic Experience / 1. Aesthetics
By 1790 aestheticians were mainly trying to explain individual artistic genius [Kemp]
21. Aesthetics / B. Nature of Art / 4. Art as Expression
Expression can be either necessary for art, or sufficient for art (or even both) [Kemp]
We don't already know what to express, and then seek means of expressing it [Kemp]
The horror expressed in some works of art could equallly be expressed by other means [Kemp]
26. Natural Theory / C. Causation / 2. Types of cause
The dispositional account explains causation, as stimulation and manifestation of dispositions [Bird]
26. Natural Theory / C. Causation / 9. General Causation / c. Counterfactual causation
The counterfactual approach makes no distinction between cause and pre-condition [Bird]