25 ideas
13886 | Later Frege held that definitions must fix a function's value for every possible argument [Frege, by Wright,C] |
9845 | We can't define a word by defining an expression containing it, as the remaining parts are a problem [Frege] |
21704 | 'Impredictative' definitions fix a class in terms of the greater class to which it belongs [Linsky,B] |
10019 | Only what is logically complex can be defined; what is simple must be pointed to [Frege] |
21705 | Reducibility says any impredicative function has an appropriate predicative replacement [Linsky,B] |
21727 | Definite descriptions theory eliminates the King of France, but not the Queen of England [Linsky,B] |
21719 | Extensionalism means what is true of a function is true of coextensive functions [Linsky,B] |
9886 | Cardinals say how many, and reals give measurements compared to a unit quantity [Frege] |
9889 | Real numbers are ratios of quantities [Frege, by Dummett] |
10553 | A number is a class of classes of the same cardinality [Frege, by Dummett] |
10020 | Frege's biggest error is in not accounting for the senses of number terms [Hodes on Frege] |
21723 | The task of logicism was to define by logic the concepts 'number', 'successor' and '0' [Linsky,B] |
21721 | Higher types are needed to distinguished intensional phenomena which are coextensive [Linsky,B] |
21703 | Types are 'ramified' when there are further differences between the type of quantifier and its range [Linsky,B] |
21714 | The ramified theory subdivides each type, according to the range of the variables [Linsky,B] |
21713 | Did logicism fail, when Russell added three nonlogical axioms, to save mathematics? [Linsky,B] |
21715 | For those who abandon logicism, standard set theory is a rival option [Linsky,B] |
9887 | Formalism misunderstands applications, metatheory, and infinity [Frege, by Dummett] |
8751 | Only applicability raises arithmetic from a game to a science [Frege] |
21729 | Construct properties as sets of objects, or say an object must be in the set to have the property [Linsky,B] |
9891 | The first demand of logic is of a sharp boundary [Frege] |
7458 | The reliability of witnesses depends on whether they benefit from their observations [Laplace, by Hacking] |
3441 | If a supreme intellect knew all atoms and movements, it could know all of the past and the future [Laplace] |
9890 | The modern account of real numbers detaches a ratio from its geometrical origins [Frege] |
11846 | If we abstract the difference between two houses, they don't become the same house [Frege] |