more from B Russell/AN Whitehead

### Single Idea 18152

#### [catalogued under 6. Mathematics / B. Foundations for Mathematics / 5. Definitions of Number / a. Defining numbers]

Full Idea

Although Russell takes numbers to be certain classes, his 'no-class' theory then eliminates all mention of classes in favour of the 'propositional functions' that define them; and in the case of the numbers these just are the numerical quantifiers.

Gist of Idea

Russell takes numbers to be classes, but then reduces the classes to numerical quantifiers

Source

report of B Russell/AN Whitehead (Principia Mathematica [1913]) by David Bostock - Philosophy of Mathematics 9.B.4

Book Reference

Bostock,David: 'Philosophy of Mathematics: An Introduction' [Wiley-Blackwell 2009], p.285