Abstract
One kind of successful communication involves the transmission of knowledge from speaker to hearer. Such testimonial knowledge transmission is usually seen as conforming to three widely held epistemological approaches: reliabilism, impartialism and evidentialism. First, a speaker must be a reliable testifier in order that she transmits knowledge, and reliability is cashed out in terms of her likelihood of speaking the truth. Second, if a certain speaker's testimony has sufficient epistemic weight to be believed by hearer1, then it should also be believed by hearer2. Third, the normative constraint here is evidentially grounded: whether or not a hearer should believe a speaker depends on the evidence the hearer has that the speaker is telling the truth. I argue that there are cases of testimonial knowledge transmission that are incompatible with these three claims. This is when one accepts the testimony of an intimate friend.