Combining Texts

Ideas for 'works', 'On Euclidean Geometry' and 'On the Principles of Indiscernibles'

unexpand these ideas     |    start again     |     choose another area for these texts

display all the ideas for this combination of texts

---

3 ideas

4. Formal Logic / F. Set Theory ST / 1. Set Theory

13455	Frege did not think of himself as working with sets [Frege, by Hart,WD]
	Full Idea: Frege did not think of himself as working with sets.
	From: report of Gottlob Frege (works [1890]) by William D. Hart - The Evolution of Logic 1
	A reaction: One can hardly blame him, given that set theory was only just being invented.

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

16895	The null set is indefensible, because it collects nothing [Frege, by Burge]
	Full Idea: Frege regarded the null set as an indefensible entity from the point of view of iterative set theory. It collects nothing.
	From: report of Gottlob Frege (works [1890]) by Tyler Burge - Frege on Apriority (with ps) 2
	A reaction: The null set defines the possibility that something could be collected. At the very least, it introduces curly brackets into the language.

4. Formal Logic / F. Set Theory ST / 5. Conceptions of Set / c. Logical sets

3328	Frege proposed a realist concept of a set, as the extension of a predicate or concept or function [Frege, by Benardete,JA]
	Full Idea: Contrary to Dedekind's anti-realism, Frege proposed a realist definition of a set as the extension of a predicate (or concept, or function).
	From: report of Gottlob Frege (works [1890]) by José A. Benardete - Metaphysics: the logical approach Ch.13