4 ideas
15943 | Limitation of Size is not self-evident, and seems too strong [Lavine on Neumann] |
Full Idea: Von Neumann's Limitation of Size axiom is not self-evident, and he himself admitted that it seemed too strong. | |
From: comment on John von Neumann (An Axiomatization of Set Theory [1925]) by Shaughan Lavine - Understanding the Infinite VII.1 |
13672 | All the axioms for mathematics presuppose set theory [Neumann] |
Full Idea: There is no axiom system for mathematics, geometry, and so forth that does not presuppose set theory. | |
From: John von Neumann (An Axiomatization of Set Theory [1925]), quoted by Stewart Shapiro - Foundations without Foundationalism 8.2 | |
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. |
9783 | While no two classes coincide in membership, there are distinct but coextensive attributes [Cartwright,R] |
Full Idea: Attributes and classes are said to be distinguished by the fact that whereas no two classes coincide in membership, there are supposed to be distinct but coextensive attributes. | |
From: Richard Cartwright (Classes and Attributes [1967], §2) | |
A reaction: This spells out the standard problem of renates and cordates, that creatures with hearts and with kidneys are precisely coextensive, but that these properties are different. Cartwright then attacks the distinction. |
468 | Musical performance can reveal a range of virtues [Damon of Ath.] |
Full Idea: In singing and playing the lyre, a boy will be likely to reveal not only courage and moderation, but also justice. | |
From: Damon (fragments/reports [c.460 BCE], B4), quoted by (who?) - where? |