The cognitive importance of testimony

As a belief source, testimony has long been held by theorists of the mind to play a deeply important role in human cognition. It is unclear, however, just why testimony has been afforded such cognitive importance. We distinguish three suggestions on the matter: the number claim, which takes testimony’s cognitive importance to be a function of the number of beliefs it typically yields, relative to other belief sources; the reliability claim, which ties the importance of testimony to its relative truth-conduciveness; and the scope claim, according to which testimony’s importance is a function of its relative representational power, non-numerically conceived. After laying out these three suggestions, we go on to argue that there is little hope of grounding testimony’s cognitive importance in either the number claim or the reliability claim. We conclude with a tentative exploration of the basis and plausibility of the scope claim.