Combining Texts

All the ideas for 'Purifications (frags)', 'works' and 'Elucidation of some points in E.Schrder'

unexpand these ideas     |    start again     |     specify just one area for these texts

---

2 ideas

1. Philosophy / A. Wisdom / 2. Wise People

15833	Tell cleverness from answers, but wisdom from questions [Mahfouz]
	Full Idea: You can tell whether a man is clever by his answers. You can tell whether a man is wise by his questions.
	From: Naguib Mahfouz (works [1998])
	A reaction: [Popped up on Twitter. I am adjusting to the 21st century] The observation is simplistic, of course, but very nice indeed.

4. Formal Logic / F. Set Theory ST / 3. Types of Set / b. Empty (Null) Set

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.