In this paper I argue that RadicalInterpretation (RI), taken to be a methodological doctrine regarding the conditions under which an interpretation of an utterance is both warranted and correct, has unacceptable implications for the conditions on (ascriptions of) understanding. The notion of understanding at play is that which underwrites the testimonial transmission of knowledge. After developing this notion I argue that, on the assumption of RI, hearers will fail to have such understanding in situations in which we should want to maintain otherwise. The overall effect of the argument is to provide a heretofore unexamined source of motivation for anti-individualistic approaches to the semantics of utterances.