display all the ideas for this combination of texts
5 ideas
10624 | The incompletability of formal arithmetic reveals that logic also cannot be completely characterized [Hale/Wright] |
Full Idea: The incompletability of formal arithmetic reveals, not arithmetical truths which are not truths of logic, but that logical truth likewise defies complete deductive characterization. ...Gödel's result has no specific bearing on the logicist project. | |
From: B Hale / C Wright (Intro to 'The Reason's Proper Study' [2001], §2 n5) | |
A reaction: This is the key defence against the claim that Gödel's First Theorem demolished logicism. |
10232 | Property extensions outstrip objects, so shortage of objects caused the Caesar problem [Cantor, by Shapiro] |
Full Idea: Cantor's theorem entails that there are more property extensions than objects. So there are not enough objects in any domain to serve as extensions for that domain. So Frege's view that numbers are objects led to the Caesar problem. | |
From: report of George Cantor (works [1880]) by Stewart Shapiro - Philosophy of Mathematics 4.6 | |
A reaction: So the possibility that Caesar might have to be a number arises because otherwise we are threatening to run out of numbers? Is that really the problem? |
18176 | Pure mathematics is pure set theory [Cantor] |
Full Idea: Pure mathematics ...according to my conception is nothing other than pure set theory. | |
From: George Cantor (works [1880], I.1), quoted by Penelope Maddy - Naturalism in Mathematics I.1 | |
A reaction: [an unpublished paper of 1884] So right at the beginning of set theory this claim was being made, before it was axiomatised, and so on. Zermelo endorsed the view, and it flourished unchallenged until Benacerraf (1965). |
10629 | If structures are relative, this undermines truth-value and objectivity [Hale/Wright] |
Full Idea: The relativization of ontology to theory in structuralism can't avoid carrying with it a relativization of truth-value, which would compromise the objectivity which structuralists wish to claim for mathematics. | |
From: B Hale / C Wright (Intro to 'The Reason's Proper Study' [2001], 3.2 n26) | |
A reaction: This is the attraction of structures which grow out of the physical world, where truth-value is presumably not in dispute. |
10628 | The structural view of numbers doesn't fit their usage outside arithmetical contexts [Hale/Wright] |
Full Idea: It is not clear how the view that natural numbers are purely intra-structural 'objects' can be squared with the widespread use of numerals outside purely arithmetical contexts. | |
From: B Hale / C Wright (Intro to 'The Reason's Proper Study' [2001], 3.2 n26) | |
A reaction: I don't understand this objection. If they refer to quantity, they are implicitly cardinal. If they name things in a sequence they are implicitly ordinal. All users of numbers have a grasp of the basic structure. |