Full Idea
One could train a dog to bark only when a bell rang and a light shone without presupposing that it possessed the concept of conjunction.
Gist of Idea
You can't infer a dog's abstract concepts from its behaviour
Source
Michael Dummett (Truth [1959], p.235)
Book Reference
'The Nature of Truth', ed/tr. Lynch, Michael P. [MIT 2001], p.235