### Single Idea 8714

#### [catalogued under 6. Mathematics / C. Sources of Mathematics / 9. Fictional Mathematics]

Full Idea

The fictionalist can say that the sense in which '2+2=4' is true is pretty much the same as the sense in which 'Oliver Twist lived in London' is true. They are true 'according to a well-known story', or 'according to standard mathematics'.

Gist of Idea

Fictionalists say 2+2=4 is true in the way that 'Oliver Twist lived in London' is true

Source

Hartry Field (Realism, Mathematics and Modality [1989], 1.1.1), quoted by Michèle Friend - Introducing the Philosophy of Mathematics 6.3

Book Reference

Field,Hartry: 'Realism, Mathematics and Modality' [Blackwell 1989], p.3

A Reaction

The roots of this idea are in Carnap. Fictionalism strikes me as brilliant, but poisonous in large doses. Novels can aspire to artistic truth, or to documentary truth. We invent a fiction, and nudge it slowly towards reality.