Combining Texts

All the ideas for 'Recent Debates on the A Priori', 'Which Logic is the Right Logic?' and 'Equality and Partiality'

expand these ideas     |    start again     |     specify just one area for these texts


24 ideas

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]
6. Mathematics / A. Nature of Mathematics / 1. Mathematics
If mathematical theories conflict, it may just be that they have different subject matter [Field,H]
20. Action / C. Motives for Action / 5. Action Dilemmas / c. Omissions
Noninterference requires justification as much as interference does [Nagel]
22. Metaethics / A. Ethics Foundations / 1. Nature of Ethics / a. Preconditions for ethics
Morality must be motivating, and not because of pre-moral motives [Nagel]
23. Ethics / B. Contract Ethics / 6. Game Theory
Game theory misses out the motivation arising from the impersonal standpoint [Nagel]
23. Ethics / D. Deontological Ethics / 3. Universalisability
In ethics we abstract from our identity, but not from our humanity [Nagel]
23. Ethics / D. Deontological Ethics / 4. Categorical Imperative
I can only universalise a maxim if everyone else could also universalise it [Nagel]
24. Political Theory / D. Ideologies / 6. Liberalism / c. Liberal equality
A legitimate system is one accepted as both impartial and reasonably partial [Nagel]
25. Social Practice / B. Equalities / 2. Political equality
Democracy is opposed to equality, if the poor are not a majority [Nagel]