Full Idea
If a man struck with aphasia can still play bridge or chess, I certainly wish to say he still has the concepts involved in the game, although he can no longer exercise them verbally.
Clarification
'Aphasia' is loss of power of speech
Gist of Idea
If someone has aphasia but can still play chess, they clearly have concepts
Source
Peter Geach (Mental Acts: their content and their objects [1957], §5)
Book Reference
Geach,Peter: 'Mental Acts: Their content and their objects' [RKP 1971], p.13
A Reaction
Geach proceeds thereafter to concentrate on language, but this caveat is crucial. To suggest that concepts are entirely verbal has always struck me as ridiculous, and an insult to our inarticulate mammalian cousins.