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Single Idea 8787

[filed under theme 6. Mathematics / B. Foundations for Mathematics / 5. Definitions of Number / e. Caesar problem ]

Full Idea

The Julius Caesar problem is the problem of supplying a criterion of application for 'number', and thereby setting it up as the concept of a genuine sort of object. (Why is Julius Caesar not a number?)

Clarification

This refers to Frege's Grundlagen §66

Gist of Idea

The Julius Caesar problem asks for a criterion for the concept of a 'number'

Source

B Hale / C Wright (Logicism in the 21st Century [2007], 3)

Book Ref

'Oxf Handbk of Philosophy of Maths and Logic', ed/tr. Shapiro,Stewart [OUP 2007], p.179


A Reaction

One response would be to deny that numbers are objects. Another would be to derive numbers from their application in counting objects, rather than the other way round. I suspect that the problem only real bothers platonists. Serves them right.


The 13 ideas with the same theme [explain why Julius Caesar can't be a number]:

Property extensions outstrip objects, so shortage of objects caused the Caesar problem [Cantor, by Shapiro]
'Julius Caesar' isn't a number because numbers inherit properties of 0 and successor [Frege, by George/Velleman]
From within logic, how can we tell whether an arbitrary object like Julius Caesar is a number? [Frege, by Friend]
Frege said 2 is the extension of all pairs (so Julius Caesar isn't 2, because he's not an extension) [Frege, by Shapiro]
Fregean numbers are numbers, and not 'Caesar', because they correlate 1-1 [Frege, by Wright,C]
One-one correlations imply normal arithmetic, but don't explain our concept of a number [Frege, by Bostock]
The words 'There are exactly Julius Caesar moons of Mars' are gibberish [Rumfitt on Frege]
Our definition will not tell us whether or not Julius Caesar is a number [Frege]
Frege makes numbers sets to solve the Caesar problem, but maybe Caesar is a set! [Bostock]
If numbers are extensions, Frege must first solve the Caesar problem for extensions [Wright,C]
The Julius Caesar problem asks for a criterion for the concept of a 'number' [Hale/Wright]
Frege solves the Caesar problem by explicitly defining each number [Maddy]
Some suggest that the Julius Caesar problem involves category mistakes [Magidor]