3 ideas
| 14238 | A class is an aggregate of objects; if you destroy them, you destroy the class; there is no empty class [Frege] |
| Full Idea: A class consists of objects; it is an aggregate, a collective unity, of them; if so, it must vanish when these objects vanish. If we burn down all the trees of a wood, we thereby burn down the wood. Thus there can be no empty class. | |
| From: Gottlob Frege (Elucidation of some points in E.Schröder [1895], p.212), quoted by Oliver,A/Smiley,T - What are Sets and What are they For? | |
| A reaction: This rests on Cantor's view of a set as a collection, rather than on Dedekind, which allows null and singleton sets. |
| 10494 | Several words may label a category; one word can name several categories; some categories lack words [Ellen] |
| Full Idea: Words are not always a good guide to the existence of categories: there may be several words which label the same categories (synonyms). and the same word can be used for quite different ideas. Some categories may exist without being labelled. | |
| From: Roy Ellen (Categories, Classification, Cogn. Anthropology [2006], I) | |
| A reaction: This is the sort of point which seems obvious to anyone outside philosophy, but which philosophers seem to find difficult to accept. Philosophers should pay much more attention to animals, and to illiterate peoples. Varieties of rice can lack labels. |
| 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? |