Some 30 years later, these two claims became the foundation stones for Bayesian decision theory. One focus of Mark Kaplan’s research has been to assess what there is for an epistemologist to learn from Bayesian decision theory. In a series of papers and the monograph, Decision Theory as Philosophy (Cambridge 1996), Kaplan has been arguing that, suitably formulated, Ramsey’s claims constitute essential contributions to epistemology.
But since the publication of that monograph, his attention has been increasingly drawn to the writings of another English philosopher, J. L. Austin. Austin, a force at Oxford for the 15 years after the end of the Second World War, was famous for having written, in “Other Minds” and Sense and Sensibilia, as if what we say while doing epistemology needs to accord faithfully with what we would say in ordinary life. Most would have used the word “infamous”. Not long after Austin’s death in 1960, there formed a durable consensus that his “ordinary language” approach to epistemology was fundamentally misguided, born of a failure to understand the nature of the epistemologist’s project. The second focus of Kaplan’s research has been to show that this consensus is based on a misreading of Austin. In another series of published works, culminating in the monograph, Austin’s Way with Skepticism: An Essay on Philosophical Method (Oxford 2018), Kaplan has argued that, far from being the product of some misunderstanding, Austin’s way of doing epistemology was in fact born of a telling critique of how epistemology has been done. Kaplan’s writings since have provided a further defense of this reading of Austin (and of Austin so read), as well as concrete examples of the progress in epistemology that can be made, once we resolve to do epistemology Austin’s way.