Full Idea
It is not true that men born blind can form no colour-concepts; a man born blind can use the word 'red' with a considerable measure of intelligence; he can show a practical grasp of the logic of the word.
Gist of Idea
Blind people can use colour words like 'red' perfectly intelligently
Source
Peter Geach (Mental Acts: their content and their objects [1957], §10)
Book Reference
Geach,Peter: 'Mental Acts: Their content and their objects' [RKP 1971], p.35
A Reaction
Weak. It is obvious that they pick up the word 'red' from the usage of sighted people, and the usage of the word doesn't guarantee a grasp of the concept, as when non-mathematicians refer to 'calculus'. Compare Idea 7377 and Idea 7866.
Related Ideas
Idea 7377 Mary learns when she sees colour, so her complete physical information had missed something [Jackson]
Idea 7866 Mary acquires new concepts; she previously thought about the same property using material concepts [Papineau]