Combining Texts

All the ideas for 'On the Philosophy of Logic', 'Symposium' and 'Model Theory'

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19 ideas

2. Reason / A. Nature of Reason / 1. On Reason
We reach 'reflective equilibrium' when intuitions and theory completely align [Fisher]
2. Reason / D. Definition / 7. Contextual Definition
The idea that groups of concepts could be 'implicitly defined' was abandoned [Hodges,W]
4. Formal Logic / E. Nonclassical Logics / 3. Many-Valued Logic
Three-valued logic says excluded middle and non-contradition are not tautologies [Fisher]
4. Formal Logic / E. Nonclassical Logics / 4. Fuzzy Logic
Fuzzy logic has many truth values, ranging in fractions from 0 to 1 [Fisher]
5. Theory of Logic / A. Overview of Logic / 5. First-Order Logic
Since first-order languages are complete, |= and |- have the same meaning [Hodges,W]
5. Theory of Logic / A. Overview of Logic / 6. Classical Logic
Classical logic is: excluded middle, non-contradiction, contradictions imply all, disjunctive syllogism [Fisher]
5. Theory of Logic / B. Logical Consequence / 4. Semantic Consequence |=
|= in model-theory means 'logical consequence' - it holds in all models [Hodges,W]
5. Theory of Logic / C. Ontology of Logic / 2. Platonism in Logic
Logic formalizes how we should reason, but it shouldn't determine whether we are realists [Fisher]
5. Theory of Logic / I. Semantics of Logic / 4. Satisfaction
|= should be read as 'is a model for' or 'satisfies' [Hodges,W]
5. Theory of Logic / J. Model Theory in Logic / 1. Logical Models
A 'structure' is an interpretation specifying objects and classes of quantification [Hodges,W]
Model theory studies formal or natural language-interpretation using set-theory [Hodges,W]
Models in model theory are structures, not sets of descriptions [Hodges,W]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / i. Cardinal infinity
First-order logic can't discriminate between one infinite cardinal and another [Hodges,W]
7. Existence / D. Theories of Reality / 10. Vagueness / g. Degrees of vagueness
We could make our intuitions about heaps precise with a million-valued logic [Fisher]
9. Objects / B. Unity of Objects / 3. Unity Problems / e. Vague objects
Vagueness can involve components (like baldness), or not (like boredom) [Fisher]
10. Modality / B. Possibility / 1. Possibility
We can't explain 'possibility' in terms of 'possible' worlds [Fisher]
10. Modality / B. Possibility / 8. Conditionals / c. Truth-function conditionals
If all truths are implied by a falsehood, then not-p might imply both q and not-q [Fisher]
10. Modality / B. Possibility / 8. Conditionals / d. Non-truthfunction conditionals
In relevance logic, conditionals help information to flow from antecedent to consequent [Fisher]
22. Metaethics / B. Value / 2. Values / h. Fine deeds
Niceratus learnt the whole of Homer by heart, as a guide to goodness [Xenophon]