Combining Texts

Ideas for 'Reason, Emotions and Good Life', 'Review of Husserl's 'Phil of Arithmetic'' and 'Introduction to Zermelo's 1930 paper'

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

display all the ideas for this combination of texts


3 ideas

6. Mathematics / A. Nature of Mathematics / 4. Using Numbers / e. Counting by correlation
Counting rests on one-one correspondence, of numerals to objects [Frege]
     Full Idea: Counting rests itself on a one-one correlation, namely of numerals 1 to n and the objects.
     From: Gottlob Frege (Review of Husserl's 'Phil of Arithmetic' [1894]), quoted by Richard G. Heck - Cardinality, Counting and Equinumerosity 3
     A reaction: Parsons observes that counting will establish a one-one correspondence, but that doesn't make it the aim of counting, and so Frege hasn't answered Husserl properly. Which of the two is conceptually prior? How do you decide.
Husserl rests sameness of number on one-one correlation, forgetting the correlation with numbers themselves [Frege]
     Full Idea: When Husserl says that sameness of number can be shown by one-one correlation, he forgets that this counting itself rests on a univocal one-one correlation, namely that between the numerals 1 to n and the objects of the set.
     From: Gottlob Frege (Review of Husserl's 'Phil of Arithmetic' [1894], p.326)
     A reaction: This is the platonist talking. Neo-logicism is attempting to build numbers just from the one-one correlation of objects.
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / g. Continuum Hypothesis
The General Continuum Hypothesis and its negation are both consistent with ZF [Hallett,M]
     Full Idea: In 1938, Gödel showed that ZF plus the General Continuum Hypothesis is consistent if ZF is. Cohen showed that ZF and not-GCH is also consistent if ZF is, which finally shows that neither GCH nor ¬GCH can be proved from ZF itself.
     From: Michael Hallett (Introduction to Zermelo's 1930 paper [1996], p.1217)