Review of Mikkel Gerken’s 2022. Scientific Testimony: Its Roles in Science and Society

Scientists assert.They testify a lot.They do so when addressing collaborators (intrascientific testimony), peers, and publics (scientific expert testimony).These activities thus are a core element of scientific collaborative practices and central to science's role in society.Scientific Testimony (2022) sets out to provide an epistemology of scientific testimony that appreciates its core functions.Scientific testimony does not reduce to scientists' assertions, however.Rather, the book convincingly argues that science journalism (science reporting) too is a species of public scientific testimony.What binds intra-scientific and forms of public scientific testimony together instead is that assertions be appropriately rooted in a sciencespecific kind of epistemic warrant: scientific justification.The epistemic norms governing provision of such justification through testimony take centre stage throughout the book.Scientific Testimony builds on an impressive array of Mikkel Gerken's previous publications in social epistemology, folk epistemology, and the specific topic at hand.It applies Gerken's rigorous epistemological tools to tackle challenges that scientific testimony encounters both within science (intra-scientific testimony) and when addressing nonscientific publics (public scientific testimony).These tools are Gerken's purist invariantist contextualism: an anti-pragmatist, semantics-based epistemic contextualism.It assumes that epistemic warrant is invariant and unique, i.e. fully determined across levels (from evidence to propositional warrant to doxastic warrant and through rejecting transmission views of epistemic warrant) and thus is non-permissive.Coherent with earlier writings, Gerken chooses not to "speak to the grand debate" (5; also 136; 182) on values in science.Yet, in virtue of its subject, Scientific Testimony is arguably involved, as will become clear below.It suggests answers to many of the same questions asked in the values and science debate and draws on a selection of its literature.