Testimonial knowledge and content preservation

Abstract

Most work in the epistemology of testimony is built upon a simple model of communication according to which, when the speaker asserts that p, the hearer must recover this very content, p. In this paper, I argue that this ‘Content Preservation Model’ of communication cannot bear the weight placed on it by contemporary work on testimony. It is popularly thought that testimonial exchanges are often successful such that we gain a great deal of knowledge through testimony. In addition, the testimonial knowledge so gained is thought to be informative: it closes off epistemic possibilities for the agent. However, in the literature on truth-conditional content, there is no theory of content that can underpin both of these commitments simultaneously if the Content Preservation Model is true. There is a minimal notion of content, which is commonly preserved in communication, but which is typically uninformative; there is a maximal notion of content, which is often informative, but which is not often preserved in communication; and, although there are moderate positions between these two extremes, these views cannot strike the right balance between informativeness and shareability. Thus, an epistemology of testimony that endorses the Content Preservation Model faces a dilemma: on the first horn, testimonial exchanges are rarely successful; on the second horn, testimonial content is rarely informative. I suggest that this dilemma motivates further exploration of alternative communicative foundations for the epistemology of testimony.