Can Testimony Generate Knowledge?

Orthodoxy in epistemology maintains that some sources of belief, e.g. perception and introspection, generate knowledge, while others, e.g. testimony and m emory, preserve knowledge. An exam ple from Jennifer Lackey – the Schoolteacher case – purports to show that testimony can generate knowledge. It is argued that Lackey’s case fails to subvert the orthodox view, for the case does not involve the generation of knowledge by testimony. A modified version of the case does. Lackey’s example illustrates the orthodox view; the revised case refutes it. The theoretical explanation of knowledge from testimony as information transmission explains how testimony transfers knowledge and why it can generate knowledge. It also revea ls the real difference between so-called “generative” and so-called “preservative” sources. The former extract information; the latter transmit information. Perception provides knowledge of the world, introspection knowledge of our selves, and mindreading knowledge of other minds. Reasoning extends knowledge beyond things we already know. Perception, introspection, mindreading, and reasoning are all ways of generating new knowledge, generating knowledge of events, facts, and states of affairs not known before. Memory differs. Memory preserves knowledge of things we already know. If I knew something at an earlier time, say on the basis of perception, and then I remember it now, then I know it now, but only because I knew it before. Testimony (the process of forming beliefs on the basis of understanding what other people say) looks like memory. If someone else knows something and tells me what they know, and I accept what they say, then I come to know it too. But I only acquire knowledge from accepting what they say if they know it already. Testimony, like memory, doesn’t generate knowledge where there was no knowledge before; testimony preserves knowledge.