more on this theme     |     more from this thinker


Single Idea 11846

[filed under theme 18. Thought / E. Abstraction / 8. Abstractionism Critique ]

Full Idea

If abstracting from the difference between my house and my neighbour's, I were to regard both houses as mine, the defect of the abstraction would soon be made clear. It may, though, be possible to obtain a concept by means of abstraction...

Gist of Idea

If we abstract the difference between two houses, they don't become the same house

Source

Gottlob Frege (Grundgesetze der Arithmetik 2 (Basic Laws) [1903], §99)

Book Ref

Frege,Gottlob: 'Translations from the Writings of Gottlob Frege', ed/tr. Geach,P/Black,M [Blackwell 1980], p.174


A Reaction

Note the important concession at the end, which shows Frege could never deny the abstraction process, despite all the modern protests by Geach and Dummett that he totally rejected it.


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]