20 ideas
8952 | We reach 'reflective equilibrium' when intuitions and theory completely align [Fisher] |
8943 | Three-valued logic says excluded middle and non-contradition are not tautologies [Fisher] |
8945 | Fuzzy logic has many truth values, ranging in fractions from 0 to 1 [Fisher] |
8951 | Classical logic is: excluded middle, non-contradiction, contradictions imply all, disjunctive syllogism [Fisher] |
8950 | Logic formalizes how we should reason, but it shouldn't determine whether we are realists [Fisher] |
13733 | Frege considered definite descriptions to be genuine singular terms [Frege, by Fitting/Mendelsohn] |
9874 | Contradiction arises from Frege's substitutional account of second-order quantification [Dummett on Frege] |
10245 | One geometry cannot be more true than another [Poincaré] |
18252 | Real numbers are ratios of quantities, such as lengths or masses [Frege] |
18271 | We can't prove everything, but we can spell out the unproved, so that foundations are clear [Frege] |
10623 | Frege defined number in terms of extensions of concepts, but needed Basic Law V to explain extensions [Frege, by Hale/Wright] |
9975 | Frege ignored Cantor's warning that a cardinal set is not just a concept-extension [Tait on Frege] |
18165 | My Basic Law V is a law of pure logic [Frege] |
8946 | We could make our intuitions about heaps precise with a million-valued logic [Fisher] |
8944 | Vagueness can involve components (like baldness), or not (like boredom) [Fisher] |
8941 | We can't explain 'possibility' in terms of 'possible' worlds [Fisher] |
8947 | If all truths are implied by a falsehood, then not-p might imply both q and not-q [Fisher] |
8949 | In relevance logic, conditionals help information to flow from antecedent to consequent [Fisher] |
9190 | A concept is a function mapping objects onto truth-values, if they fall under the concept [Frege, by Dummett] |
13665 | Frege took the study of concepts to be part of logic [Frege, by Shapiro] |