Recent interest in the epistemology of testimony can be traced to C. A. J. Coady's Testimony: A Philosophical Study (1992) and then a collection of papers edited by Bimal Krishna Matilal and Arindam Chakrabarti, Knowing from Words (1994). These two volumes framed several issues in the epistemology of testimony and largely set the agenda for work in that area over the next two decades. -/- One major issue in this literature is whether testimonial knowledge can be "reduced" to some other (...) kind of knowledge: Is testimonial knowledge sui generis, requiring its own distinctive treatment, or is testimonial knowledge merely an instance of, for example, inductive knowledge, requiring no special epistemology over and above that required for inductive knowledge in general? One way that testimonial knowledge might be special is that it involves social elements that make it distinctive. This possibility raises further issues that have been prominent in the literature: In what ways is testimonial knowledge a social phenomenon, and what are the consequences of this for the epistemology of testimony and for epistemology more generally? (shrink)

This paper introduces a multi-modal polymorphic type theory to model epistemic processes characterized by trust, defined as a second-order relation affecting the communication process between sources and a receiver. In this language, a set of senders is expressed by a modal prioritized context, whereas the receiver is formulated in terms of a contextually derived modal judgement. Introduction and elimination rules for modalities are based on the polymorphism of terms in the language. This leads to a multi-modal non-homogeneous version of a (...) type theory, in which we show the embedding of the modal operators into standard group knowledge operators. (shrink)