The fact that much of our knowledge is gained through the testimony of others challenges a certain form of epistemic individualism. We are clearly not autonomous knowers. But the discussion surrounding testimony has maintained a commitment to what I have elsewhere called epistemic agent individualism. Both the reductionist and the anti-reductionist have focused their attention on the testimony of individuals. But groups, too, are sources of testimony - or so I shall argue. If groups can be testifiers, a natural question to ask is whether our beliefs based on the testimony of groups are ever justified and whether such a justification is to be conferred inferentially or non-inferentially. I consider and dismiss the possibility of extending an anti-reductionist account of justification to our group testimonial beliefs. I also argue against a version of reductionism that would have our group testimonial beliefs justified only in so far as we were able to monitor the trustworthiness of members of the group. However, there are forms of reductionism that can be extended to make sense of the justification of our group testimonial beliefs. There are mechanisms for monitoring the trustworthiness and competency of a group (rather than its members) and, further, a variety of background beliefs allow us to assess the testimony of a group for reliability.
Tollefsen, D. (2007). Group testimony. Social Epistemology, 21 (3), 299-311. https://doi.org/10.1080/02691720701674163