When is consensus knowledge based?

distinguishing shared knowledge from mere agreement

Boaz Miller

pp. 1293-1316

in: Kristoffer Ahlstrom-Vij, Klemens Kappel, Nikolaj Pedersen (eds), The epistemology of inclusiveness, Synthese 190 (7), 2013.

Abstract

Scientific consensus is widely deferred to in public debates as a social indicator of the existence of knowledge. However, it is far from clear that such deference to consensus is always justified. The existence of agreement in a community of researchers is a contingent fact, and researchers may reach a consensus for all kinds of reasons, such as fighting a common foe or sharing a common bias. Scientific consensus, by itself, does not necessarily indicate the existence of shared knowledge among the members of the consensus community. I address the question of under what conditions it is likely that a consensus is in fact knowledge based. I argue that a consensus is likely to be knowledge based when knowledge is the best explanation of the consensus, and I identify three conditions—social calibration, apparent consilience of evidence, and social diversity, for knowledge being the best explanation of a consensus.