Abstract

Nelson Goodman's own solution to his new riddle of induction turns on the degree to which predicates are entrenched in our use of language. However, this solution requires that judgements concerning the degree to which a predicate is entrenched can be made independently of any canon of perceptible similarity. I argue that this requirement cannot be met. The riddle itself depends upon the claim that since ‘green’ can be defined positionally in terms of ‘grue’ and ‘bleen’, ‘grue’ and ‘bleen’ are symmetrically related to ‘green’ and ‘blue’, and positionality is therefore ‘an entirely relative matter’. However, in order to establish that positionality is an entirely relative matter, we would need to provide a non‐positional definition of ‘grue’, rather than a positional definition of ‘green’. We therefore need to decide whether ‘grue’ can be defined ostensively by means of a single sample, as ‘green’ can. I argue that any attempt to provide such a definition is bound to fail, and hence the new riddle of induction does not reveal that ‘the roots of inductive validity are to be found in our use of language’.