more from this thinker     |     more from this text


Single Idea 9644

[filed under theme 6. Mathematics / B. Foundations for Mathematics / 6. Mathematics as Set Theory / b. Mathematics is not set theory ]

Full Idea

The basic definition of a graph can be given in set-theoretic terms,...but then what could an unlabelled graph be?

Gist of Idea

When graphs are defined set-theoretically, that won't cover unlabelled graphs

Source

James Robert Brown (Philosophy of Mathematics [1999], Ch. 7)

Book Ref

Brown,James Robert: 'Philosophy of Mathematics' [Routledge 2002], p.105


A Reaction

An unlabelled graph will at least need a verbal description for it to have any significance at all. My daily mood-swings look like this....


The 14 ideas with the same theme [denial that mathematics is just set theory]:

If numbers can be derived from logic, then set theory is superfluous [Frege, by Burge]
The theory of classes is superfluous in mathematics [Wittgenstein]
Disputes about mathematical objects seem irrelevant, and mathematicians cannot resolve them [Benacerraf, by Friend]
No particular pair of sets can tell us what 'two' is, just by one-to-one correlation [Benacerraf, by Lowe]
If ordinal numbers are 'reducible to' some set-theory, then which is which? [Benacerraf]
You can ask all sorts of numerical questions about any one given set [Yourgrau]
We can't use sets as foundations for mathematics if we must await results from the upper reaches [Yourgrau]
Set-theoretic imperialists think sets can represent every mathematical object [Fine,K]
Mathematical foundations may not be sets; categories are a popular rival [Shapiro]
Sets exist where their elements are, but numbers are more like universals [Maddy]
Number theory doesn't 'reduce' to set theory, because sets have number properties [Maddy]
Set theory may represent all of mathematics, without actually being mathematics [Brown,JR]
When graphs are defined set-theoretically, that won't cover unlabelled graphs [Brown,JR]
Numbers are properties, not sets (because numbers are magnitudes) [Hossack]