3 ideas
| 8920 | Equivalence relations are reflexive, symmetric and transitive, and classify similar objects [Lipschutz] |
| Full Idea: A relation R on a non-empty set S is an equivalence relation if it is reflexive (for each member a, aRa), symmetric (if aRb, then bRa), and transitive (aRb and bRc, so aRc). It tries to classify objects that are in some way 'alike'. | |
| From: Seymour Lipschutz (Set Theory and related topics (2nd ed) [1998], 3.9) | |
| A reaction: So this is an attempt to formalise the common sense notion of seeing that two things have something in common. Presumably a 'way' of being alike is going to be a property or a part |
| 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 |
| 9287 | Bruno said that ancient Egyptian magic was the true religion [Bruno, by Yates] |
| Full Idea: Giordano Bruno maintained that the magical Egyptian religion of the world was not only the most ancient but also the only true religion, which both Judaism and Christianity had obscured and corrupted. | |
| From: report of Giordano Bruno (works [1590]) by Frances A. Yates - Giordano Bruno and Hermetic Tradition Ch.1 | |
| A reaction: His beliefs were based on the Hermetic writings. No wonder he was burned at the stake. Atheists now lay flowers at his memorial in Rome. The sixteenth century was when the hunt for alternatives to established religion began. |