**See**: [[Bleen and grue]]. %% claude: ## Implications 1. **Arbitrariness of Predicates**: The riddle suggests that our choice of predicates (like "green" over "grue") might be arbitrary or based on factors outside of pure logic. 2. **Projectibility**: Goodman introduced the concept of "projectible" predicates - those that can be legitimately used in inductive reasoning. But determining which predicates are projectible remains a challenge. 3. **Entrenchment**: Goodman proposed that we favor predicates like "green" over "grue" because they are more entrenched in our language and thinking, not because of any inherent logical superiority. 4. **Challenge to Induction**: The riddle casts doubt on the reliability of inductive reasoning, which is fundamental to scientific inquiry and everyday decision-making.