AGM, Ranking Theory, and the Many Ways to Cope with Examples

Abstract

The paper first explains how the ranking-theoretic belief change or conditionalization rules entail all of the standard AGM belief revision and contraction axioms. Those axioms have met a lot of objections and counter-examples, which thus extend to ranking theory as well. The paper argues for a paradigmatic set of cases that the counter-examples can be well accounted for with various pragmatic strategies while maintaining the axioms. So, one point of the paper is to save AGM belief revision theory as well as ranking theory. The other point, however, is to display how complex the pragmatic interaction of belief change and utterance meaning may be; it should be systematically and not only paradigmatically explored.