41 ideas
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] |
17979 | Research shows perceptual discrimination is sharper at category boundaries [Murphy] |
18690 | Induction is said to just compare properties of categories, but the type of property also matters [Murphy] |
17980 | The main theories of concepts are exemplar, prototype and knowledge [Murphy] |
17973 | The theoretical and practical definitions for the classical view are very hard to find [Murphy] |
17969 | The classical definitional approach cannot distinguish typical and atypical category members [Murphy] |
17970 | Classical concepts follow classical logic, but concepts in real life don't work that way [Murphy] |
17971 | Classical concepts are transitive hierarchies, but actual categories may be intransitive [Murphy] |
17972 | The classical core is meant to be the real concept, but actually seems unimportant [Murphy] |
17975 | There is no 'ideal' bird or dog, and prototypes give no information about variability [Murphy] |
17976 | Prototypes are unified representations of the entire category (rather than of members) [Murphy] |
18691 | The prototype theory uses observed features, but can't include their construction [Murphy] |
17983 | The prototype theory handles hierarchical categories and combinations of concepts well [Murphy] |
17985 | Prototypes theory of concepts is best, as a full description with weighted typical features [Murphy] |
17986 | Learning concepts is forming prototypes with a knowledge structure [Murphy] |
17974 | The most popular theories of concepts are based on prototypes or exemplars [Murphy] |
17977 | The exemplar view of concepts says 'dogs' is the set of dogs I remember [Murphy] |
17982 | Exemplar theory struggles with hierarchical classification and with induction [Murphy] |
17981 | Children using knowing and essentialist categories doesn't fit the exemplar view [Murphy] |
17984 | Conceptual combination must be compositional, and can't be built up from exemplars [Murphy] |
17987 | The concept of birds from exemplars must also be used in inductions about birds [Murphy] |
17978 | We do not learn concepts in isolation, but as an integrated part of broader knowledge [Murphy] |
18687 | Concepts with familiar contents are easier to learn [Murphy] |
18688 | Some knowledge is involved in instant use of categories, other knowledge in explanations [Murphy] |
18689 | People categorise things consistent with their knowledge, even rejecting some good evidence [Murphy] |
6005 | Animals are dangerous and nourishing, and can't form contracts of justice [Hermarchus, by Sedley] |