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Single Idea 8751

[filed under theme 6. Mathematics / C. Sources of Mathematics / 7. Formalism ]

Full Idea

It is applicability alone which elevates arithmetic from a game to the rank of a science.

Gist of Idea

Only applicability raises arithmetic from a game to a science

Source

Gottlob Frege (Grundgesetze der Arithmetik 2 (Basic Laws) [1903], §91), quoted by Stewart Shapiro - Thinking About Mathematics 6.1.2

Book Ref

Shapiro,Stewart: 'Thinking About Mathematics' [OUP 2000], p.147


A Reaction

This is the basic objection to Formalism. It invites the question of why it is applicable, which platonists like Frege don't seem to answer (though Plato himself has reality modelled on the Forms). This is why I like structuralism.


The 12 ideas from 'Grundgesetze der Arithmetik 2 (Basic Laws)'

Later Frege held that definitions must fix a function's value for every possible argument [Frege, by Wright,C]
Real numbers are ratios of quantities [Frege, by Dummett]
A number is a class of classes of the same cardinality [Frege, by Dummett]
Frege's biggest error is in not accounting for the senses of number terms [Hodes on Frege]
Cardinals say how many, and reals give measurements compared to a unit quantity [Frege]
The modern account of real numbers detaches a ratio from its geometrical origins [Frege]
The first demand of logic is of a sharp boundary [Frege]
Only what is logically complex can be defined; what is simple must be pointed to [Frege]
We can't define a word by defining an expression containing it, as the remaining parts are a problem [Frege]
Formalism misunderstands applications, metatheory, and infinity [Frege, by Dummett]
Only applicability raises arithmetic from a game to a science [Frege]
If we abstract the difference between two houses, they don't become the same house [Frege]