25 ideas
14600 | Analysis aims at secure necessary and sufficient conditions [Schaffer,J] |
14603 | 'Reification' occurs if we mistake a concept for a thing [Schaffer,J] |
14607 | T adds □p→p for reflexivity, and is ideal for modeling lawhood [Schaffer,J] |
10775 | The axiom of choice now seems acceptable and obvious (if it is meaningful) [Tharp] |
10766 | Logic is either for demonstration, or for characterizing structures [Tharp] |
10767 | Elementary logic is complete, but cannot capture mathematics [Tharp] |
10769 | Second-order logic isn't provable, but will express set-theory and classic problems [Tharp] |
10762 | In sentential logic there is a simple proof that all truth functions can be reduced to 'not' and 'and' [Tharp] |
10776 | The main quantifiers extend 'and' and 'or' to infinite domains [Tharp] |
10774 | There are at least five unorthodox quantifiers that could be used [Tharp] |
10777 | Skolem mistakenly inferred that Cantor's conceptions were illusory [Tharp] |
10773 | The Löwenheim-Skolem property is a limitation (e.g. can't say there are uncountably many reals) [Tharp] |
10765 | Soundness would seem to be an essential requirement of a proof procedure [Tharp] |
10763 | Completeness and compactness together give axiomatizability [Tharp] |
10770 | If completeness fails there is no algorithm to list the valid formulas [Tharp] |
10771 | Compactness is important for major theories which have infinitely many axioms [Tharp] |
10772 | Compactness blocks infinite expansion, and admits non-standard models [Tharp] |
10764 | A complete logic has an effective enumeration of the valid formulas [Tharp] |
10768 | Effective enumeration might be proved but not specified, so it won't guarantee knowledge [Tharp] |
9226 | If mathematical theories conflict, it may just be that they have different subject matter [Field,H] |
14604 | If a notion is ontologically basic, it should be needed in our best attempt at science [Schaffer,J] |
14599 | Three types of reduction: Theoretical (of terms), Definitional (of concepts), Ontological (of reality) [Schaffer,J] |
14605 | Tropes are the same as events [Schaffer,J] |
14601 | Individuation aims to count entities, by saying when there is one [Schaffer,J] |
14606 | Only ideal conceivability could indicate what is possible [Schaffer,J] |