more from Brian Ellis

Single Idea 5485

[catalogued under 14. Science / C. Induction / 5. Paradoxes of Induction / a. Grue problem]

Full Idea

Emeralds cannot all turn blue in 2050 (as Nelson Goodman envisaged), because to do so they would have to have an extrinsically variable nature.


'Extrinsically' here means imposed from the outside

Gist of Idea

Emeralds are naturally green, and only an external force could turn them blue


Brian Ellis (The Philosophy of Nature: new essentialism [2002], Ch.7)

Book Reference

Ellis,Brian: 'The Philosophy of Nature: new essentialism' [Acumen 2002], p.137

A Reaction

I was never very impressed by the 'grue' problem, probably for this reason, but also because Goodman probably thought predicates and properties are the same thing, which they aren't (Idea 5457).

Related Idea

Idea 5457 Predicates assert properties, values, denials, relations, conventions, existence and fabrications [Ellis, by PG]