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Single Idea 13672

[filed under theme 6. Mathematics / B. Foundations for Mathematics / 6. Mathematics as Set Theory / a. Mathematics is set theory ]

Full Idea

There is no axiom system for mathematics, geometry, and so forth that does not presuppose set theory.

Gist of Idea

All the axioms for mathematics presuppose set theory

Source

John von Neumann (An Axiomatization of Set Theory [1925]), quoted by Stewart Shapiro - Foundations without Foundationalism 8.2

Book Ref

Shapiro,Stewart: 'Foundations without Foundationalism' [OUP 1991], p.209


A Reaction

Von Neumann was doubting whether set theory could have axioms, and hence the whole project is doomed, and we face relativism about such things. His ally was Skolem in this.


The 10 ideas from John von Neumann

Limitation of Size is not self-evident, and seems too strong [Lavine on Neumann]
All the axioms for mathematics presuppose set theory [Neumann]
For Von Neumann the successor of n is n U {n} (rather than {n}) [Neumann, by Maddy]
Von Neumann numbers are preferred, because they continue into the transfinite [Maddy on Neumann]
Each Von Neumann ordinal number is the set of its predecessors [Neumann, by Lavine]
A von Neumann ordinal is a transitive set with transitive elements [Neumann, by Badiou]
Von Neumann treated cardinals as a special sort of ordinal [Neumann, by Hart,WD]
Von Neumann defined ordinals as the set of all smaller ordinals [Neumann, by Poundstone]
Von Neumann wanted mathematical functions to replace sets [Neumann, by Benardete,JA]
Von Neumann defines each number as the set of all smaller numbers [Neumann, by Blackburn]