Expert testimony and the social transmission of scientific knowledge

This project explores the evidential significance of trust in expert testimony in science, grounded in modern physics. I illustrate how attention to social considerations has evidential relevance and so identify common ground for philosophers and others interested in science. I articulate conceptions of testimony as evidential, of epistemic trust as compatible with critical assessment, and of expertise as compatible with epistemic interdependence. This allows us to see trust in expert testimony as epistemologically fertile and subject to rational scrutiny, and more generally helps clarify the difference between social reputation and rational authority while exploring their interconnection.;So grounded I consider how social circumstances inform the trustworthiness of scientific expert testimony. One such circumstance concerns unmatched expertise, where a community must evaluate a speaker whose special expertise surpasses everyone else. Here I investigate Eddington's eclipse expedition testing Einstein's general theory of relativity and prediction of starlight deflection. Circumstances isolated Eddington as unmatched British relativity expert and his expedition as an unmatched evidential source on general relativity. Despite the epistemic inequality involved, I argue, the acceptance of Eddington's pro-relativity testimony by his British contemporaries did not require entirely uncritical deference to his expertise: Eddington's claims were importantly corroborated by community members with overlapping expertise.;A second circumstance concerns conflicting expertise. Can experts on opposite sides reasonably disagree? What can non-experts do given conflicting expertise? Here I investigate the dispute over Weber's search for gravity waves. Weber's claim to have detected gravity waves was greeted with optimism; but soon his field rejected his claim though he remained convinced. Engaging conflicting analyses by Franklin and Collins, I find common ground between them and explain how Weber's and his peers' stances could both be reasonable. I use this case to evaluate philosophical proposals for non-expert assessment of expert disagreement with implications for indirect indicators of expert trustworthiness. This case enables fruitful engagement with epistemology of disagreement and science studies scholarship on relativistic methodology; I argue for the possibility of reasonable disagreement in experimental science and critique Collins's methodological relativism contrasted against other relativisms and my social epistemological approach.