Epistemological depth in a GM crops controversy

•The two sides in the GM crop yields debate appeal to different sets of evidence.•These two sets of evidence correspond to two rival epistemological frameworks.•Even if both sides accepted the same epistemological framework they would disagree about the context of application.•For these reasons, appeals to “the evidence” are insufficient to resolve the debate.

This paper examines the scientific controversy over the yields of genetically modified [GM] crops as a case study in epistemologically deep disagreements. Appeals to “the evidence” are inadequate to resolve such disagreements; not because the interlocutors have radically different metaphysical views (as in cases of incommensurability), but instead because they assume rival epistemological frameworks and so have incompatible views about what kinds of research methods and claims count as evidence. Specifically, I show that, in the yield debate, proponents and opponents of GM crops cite two different sets of claims as evidence, which correspond to two rival epistemological frameworks, classical experimental epistemology and Nancy Cartwright's evidence for use. I go on to argue that, even if both sides of the debate accepted Cartwright's view, they might still disagree over what counts as evidence, because evidence for use ties standards of evidence to what is sometimes called the “context of application.”