3 ideas
23505 | Aristotelian logic cannot express 'Everyone loves someone' [White,RM] |
Full Idea: There is no way within Aristotelian logic that you can give a proper expression for the logical form of such a proposition as 'Everyone loves someone'. | |
From: Roger M. White (Wittgenstein's 'Tractatus Logico-Philosophicus' [2006], 1 'Frege') | |
A reaction: This needs a combination of two different quantifiers. |
3061 | Anaxarchus said that he was not even sure that he knew nothing [Anaxarchus, by Diog. Laertius] |
Full Idea: Anaxarchus said that he was not even sure that he knew nothing. | |
From: report of Anaxarchus (fragments/reports [c.340 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 09.10.1 |
7006 | Observing irrelevant items supports both 'all x are y' and 'all x are non-y', revealing its absurdity [Schofield,J] |
Full Idea: Although Hempel's raven paradox produces an absurdity of irrelevant observations, we can ignore it because (unlike good observations) observing a white handbag supports the contradictions of 'ravens are black' and 'ravens are non-black'. | |
From: Jonathan Schofield (talk [2005]), quoted by PG - Db (ideas) | |
A reaction: The idea of 'eliminating it from our enquiries' cannot be totally irrational (e.g. in detective work), but it is only seriously sensible in a restricted domain (such as a country house) |