Combining Texts

All the ideas for 'Which Logic is the Right Logic?', 'Truth Rehabilitated' and 'Resurrecting Biological Essentialism'

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29 ideas

3. Truth / A. Truth Problems / 3. Value of Truth
Without truth, both language and thought are impossible [Davidson]
Plato's Forms confused truth with the most eminent truths, so only Truth itself is completely true [Davidson]
Truth can't be a goal, because we can neither recognise it nor confim it [Davidson]
3. Truth / C. Correspondence Truth / 1. Correspondence Truth
Correspondence can't be defined, but it shows how truth depends on the world [Davidson]
3. Truth / F. Semantic Truth / 1. Tarski's Truth / c. Meta-language for truth
When Tarski defines truth for different languages, how do we know it is a single concept? [Davidson]
3. Truth / H. Deflationary Truth / 2. Deflationary Truth
Disquotation only accounts for truth if the metalanguage contains the object language [Davidson]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / j. Axiom of Choice IX
The axiom of choice now seems acceptable and obvious (if it is meaningful) [Tharp]
5. Theory of Logic / A. Overview of Logic / 1. Overview of Logic
Logic is either for demonstration, or for characterizing structures [Tharp]
5. Theory of Logic / A. Overview of Logic / 5. First-Order Logic
Elementary logic is complete, but cannot capture mathematics [Tharp]
5. Theory of Logic / A. Overview of Logic / 7. Second-Order Logic
Second-order logic isn't provable, but will express set-theory and classic problems [Tharp]
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / b. Basic connectives
In sentential logic there is a simple proof that all truth functions can be reduced to 'not' and 'and' [Tharp]
5. Theory of Logic / G. Quantification / 2. Domain of Quantification
The main quantifiers extend 'and' and 'or' to infinite domains [Tharp]
5. Theory of Logic / G. Quantification / 7. Unorthodox Quantification
There are at least five unorthodox quantifiers that could be used [Tharp]
5. Theory of Logic / J. Model Theory in Logic / 3. Löwenheim-Skolem Theorems
Skolem mistakenly inferred that Cantor's conceptions were illusory [Tharp]
The Löwenheim-Skolem property is a limitation (e.g. can't say there are uncountably many reals) [Tharp]
5. Theory of Logic / K. Features of Logics / 3. Soundness
Soundness would seem to be an essential requirement of a proof procedure [Tharp]
5. Theory of Logic / K. Features of Logics / 4. Completeness
Completeness and compactness together give axiomatizability [Tharp]
5. Theory of Logic / K. Features of Logics / 5. Incompleteness
If completeness fails there is no algorithm to list the valid formulas [Tharp]
5. Theory of Logic / K. Features of Logics / 6. Compactness
Compactness is important for major theories which have infinitely many axioms [Tharp]
Compactness blocks infinite expansion, and admits non-standard models [Tharp]
5. Theory of Logic / K. Features of Logics / 8. Enumerability
A complete logic has an effective enumeration of the valid formulas [Tharp]
Effective enumeration might be proved but not specified, so it won't guarantee knowledge [Tharp]
7. Existence / D. Theories of Reality / 8. Facts / e. Facts rejected
If we try to identify facts precisely, they all melt into one (as the Slingshot Argument proves) [Davidson]
9. Objects / D. Essence of Objects / 10. Essence as Species
Essentialism concerns the nature of a group, not its category [Devitt]
Things that gradually change, like species, can still have essences [Devitt]
19. Language / A. Nature of Meaning / 4. Meaning as Truth-Conditions
Knowing the potential truth conditions of a sentence is necessary and sufficient for understanding [Davidson]
19. Language / A. Nature of Meaning / 6. Meaning as Use
It could be that the use of a sentence is explained by its truth conditions [Davidson]
27. Natural Reality / G. Biology / 5. Species
We name species as small to share properties, but large enough to yield generalisations [Devitt]
Species are phenetic, biological, niche, or phylogenetic-cladistic [Devitt, by PG]