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 |
22086 | The most important aspect of a human being is not reason, but passion [Kierkegaard, by Carlisle] |
Full Idea: Kierkegaard insisted that the most important aspect of a human being is not reason, but passion. | |
From: report of Søren Kierkegaard (works [1845]) by Clare Carlisle - Kierkegaard: a guide for the perplexed Intro | |
A reaction: Hume comes to mind for a similar view, but in character Hume was far more rational than Kierkegaard. |
16570 | Elements are found last in dismantling bodies, and first in generating them [Albert of Saxony] |
Full Idea: On one possible description, an element is what is found last when bodies are taken apart, and what is found first when bodies are generated. | |
From: Albert of Saxony (On 'Generation and Corruption' [1356], II.3), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 2.1 |