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Ideas for 'Mind and Its Place in Nature', 'Logicism in the 21st Century' and 'works'

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2 ideas

6. Mathematics / B. Foundations for Mathematics / 5. Definitions of Number / d. Hume's Principle
Neo-logicism founds arithmetic on Hume's Principle along with second-order logic [Hale/Wright]
     Full Idea: The result of joining Hume's Principle to second-order logic is a consistent system which is a foundation for arithmetic, in the sense that all the fundamental laws of arithmetic are derivable within it as theorems. This seems a vindication of logicism.
     From: B Hale / C Wright (Logicism in the 21st Century [2007], 1)
     A reaction: The controversial part seems to be second-order logic, which Quine (for example) vigorously challenged. The contention against most attempts to improve Frege's logicism is that they thereby cease to be properly logical.
6. Mathematics / B. Foundations for Mathematics / 5. Definitions of Number / e. Caesar problem
The Julius Caesar problem asks for a criterion for the concept of a 'number' [Hale/Wright]
     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?)
     From: B Hale / C Wright (Logicism in the 21st Century [2007], 3)
     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.