There are two different sorts of epistemological projects that have been important in the history of philosophy. One project aims to provide an epistemological framework that evaluates belief tokens. This project, which includes theories of justification and knowledge, has dominated English-speaking epistemology for much of the past century. The second project aims to provide an epistemological framework that evaluates reasoning rules, methods, or strategies. This project has been pursued by philosophers of science (e.g., Mill, Popper, Kitcher, Laudan) and by people with interests in artificial systems (e.g., Bayesians).

What is the proper way to think about the relationship between these different epistemological projects? Here is a view I think is quite prevalent among philosophers: “Theoretical epistemology proper is concerned with the first project – with accounting for knowledge and justification. This project provides the correct epistemological end or goal of cognition. The second project is engineering. It investigates the best means we have for achieving the appropriate ends provided by theoretical epistemology. In this way, the theoretical project is prior to or more fundamental than the applied project. This is not intended in an insulting way. The applied, engineering project is very difficult, very interesting, and can raise very tricky philosophical issues about how to properly weigh various norms or values (including epistemological norms or values) against one another. What’s more, a complete, useful epistemology must include both a theoretical and applied component. But theories of knowledge and justification do not depend on theories of reasoning excellence, while theories of reasoning excellence depend essentially on theories of (or perhaps just implicit assumptions about) knowledge and justification.”

My goal in this talk is to argue that this view about the relationship between these epistemological projects is mistaken.