Character Matching and the Locke Pocket of Belief

Abstract

The Lockean thesis of full belief maintains that an individual believes a proposition just when he has a high enough level of confidence. The trouble with the Lockean thesis, according to probabilists like Richard Jeffrey, is that it licenses throwing away perfectly good information. Some proponents of the Lockean thesis—call them Harmonious Lockeans—maintain that reconciling qualitative and quantitative belief will need to occur on Jeffrey’s terms. To this end, Scott Sturgeon has advanced a normative principle for Harmonious Lockeanism called Character Matching, which this essay criticizes through means of a counterexample and, with the help of a model of Henry Kyburg’s, an alternative model for Harmonious Lockean belief that turns the Principle of Character Matching inside out. The upshot is that the character of evidence provides no corresponding normative constraint on the character of belief. A further consequence is that the disposition to fully believe, while dependent on a subject’s practical interests, does not depend upon the total magnitude of the stake put at risk.