Testimony by Presupposition

Abstract Testimony is a source of knowledge. A speaker asserts what hearer may therefore come to know. Assertion has widely been treated as the exclusive or at least paradigmatic vehicle for testimony. I argue that we testify not only by asserting something, but also taking something granted within some other utterance. In philosophy language, this called semantic presupposition. The very reasons leading theorists testimony have thinking assertion can be are equally presupposition