In the second paragraph of "What is a Theory of Meaning?" Dummett writes: "I share the belief that this is the most fruitful approach to the problems within this area of philosophy, although I should not feel capable of giving a demonstration that this was so to someone who denied it (...)". Who is Dummett referring to?
http://isites.harvard.edu/fs/docs/icb.topic255987.files/Dummett---What-is-a-Theory-of-Meaning-I.pdf