Comparativism and the Measurement of Partial Belief

Abstract

According to comparativism, degrees of belief are reducible to a system of purely ordinal comparisons of relative confidence. (For example, being more confident that P than that Q, or being equally confident that P and that Q.) In this paper, I raise several general challenges for comparativism, relating to (1) its capacity to illuminate apparently meaningful claims regarding intervals and ratios of strengths of belief, (2) its capacity to draw enough intuitively meaningful and theoretically relevant distinctions between doxastic states, and (3) its capacity to handle common instances of irrationality.