3 ideas
17750 | The first clear proof of the consistency of the first order predicate logic was in 1928 [Hilbert/Ackermann, by Walicki] |
19087 | The meaning or purport of a symbol is all the rational conduct it would lead to [Peirce] |
3284 | There is no one theory of how to act (or what to believe) [Nagel] |