3 ideas
18465 | An 'equivalence' relation is one which is reflexive, symmetric and transitive [Kunen] |
Full Idea: R is an equivalence relation on A iff R is reflexive, symmetric and transitive on A. | |
From: Kenneth Kunen (The Foundations of Mathematics (2nd ed) [2012], I.7.1) |
22307 | Propositions don't name facts, because two opposed propositions can match one fact [Russell] |
Full Idea: It is perfectly evident that a proposition is not the name for a fact, from the mere circumstance that there are two propositions corresponding to each fact. 'Socrates is dead' and 'Socrates is not dead' correspond to the same fact. | |
From: Bertrand Russell (Papers of 1918 [1918], VIII.136), quoted by Michael Potter - The Rise of Analytic Philosophy 1879-1930 42 'Prop' | |
A reaction: He finally reaches in 1918 what now looks fairly obvious. The idea that a proposition is part of the world is absurd. We should call the parts of the world 'facts' (despite vagueness and linguistic dependence in such things). Propositions are thoughts. |
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? |