简介

In 1926, the Cambridge philosopher and mathematician Frank P. Ramsey wrote a paper, "Truth and Probability," in which he made two startling claims. He claimed that (a) if they are to be consistent, a person's degrees of belief in propositions (which measure how confident she is in the truth of the propositions) must obey the probability calculus; and (b) one can establish as much by an argument that appeals to nothing but principles that specify conditions under which a person's preferences count as rational. Some thirty years later, these two claims became the foundation stones for Bayesian decision theory . One focus of my research has been to assess what there is for an epistemologist to learn from Bayesian decision theory. My contention is that, suitably formulated, Ramsey's claims constitute essential contributions to epistemology-including epistemology as we ordinarily think of it: the study of justified belief and knowledge. I argued as much in my book, Decision Theory as Philosophy (Cambridge 1996). And I continue to work out the epistemological import of Ramsey's ideas for contemporary epistemology.