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Single Idea 17442

[filed under theme 6. Mathematics / B. Foundations for Mathematics / 5. Definitions of Number / d. Hume's Principle ]

Full Idea

Frege's answer is that the concept of number is fundamentally bound up with the notion of one-one correspondence.

Gist of Idea

Frege thinks number is fundamentally bound up with one-one correspondence

Source

report of Gottlob Frege (Grundlagen der Arithmetik (Foundations) [1884]) by Richard G. Heck - Cardinality, Counting and Equinumerosity 1

Book Ref

-: 'Notre Dame Journal of Formal Logic' [-], p.190


A Reaction

Birds seem to find a mate with virtually no concept of number. I'm beginning to think that the essence of numbers is that they are both ordinals and cardinals. Frege, of course, thinks identity is basic to metaphysics.


The 19 ideas with the same theme [view that one-one correspondence is basis of numbers]:

Two numbers are equal if all of their units correspond to one another [Hume]
'The number of Fs' is the extension (a collection of first-level concepts) of the concept 'equinumerous with F' [Frege, by George/Velleman]
Frege's cardinals (equivalences of one-one correspondences) is not permissible in ZFC [Frege, by Wolf,RS]
Hume's Principle fails to implicitly define numbers, because of the Julius Caesar [Frege, by Potter]
Frege thinks number is fundamentally bound up with one-one correspondence [Frege, by Heck]
A number is something which characterises collections of the same size [Russell]
Many things will satisfy Hume's Principle, so there are many interpretations of it [Bostock]
There are many criteria for the identity of numbers [Bostock]
Hume's Principle is a definition with existential claims, and won't explain numbers [Bostock]
We derive Hume's Law from Law V, then discard the latter in deriving arithmetic [Wright,C, by Fine,K]
Frege has a good system if his 'number principle' replaces his basic law V [Wright,C, by Friend]
Wright says Hume's Principle is analytic of cardinal numbers, like a definition [Wright,C, by Heck]
It is 1-1 correlation of concepts, and not progression, which distinguishes natural number [Wright,C]
Neo-logicism founds arithmetic on Hume's Principle along with second-order logic [Hale/Wright]
If Hume's Principle can define numbers, we needn't worry about its truth [Fine,K]
Hume's Principle is either adequate for number but fails to define properly, or vice versa [Fine,K]
Simple counting is more basic than spotting that one-to-one correlation makes sets equinumerous [Lowe]
Fs and Gs are identical in number if they one-to-one correlate with one another [Lowe]
Frege's Theorem shows the Peano Postulates can be derived from Hume's Principle [George/Velleman]