A Guided Tour through the Cosmos of Ranking Theory

Ranking theory is the first legitimate sister of probability theory. That is, it is a dynamic theory of belief and as such of comparable fundamentality and generality to Bayesianism. Ranks also are degrees of belief ranging from - to + infinity, behaving in many ways similar and in characteristic ways unlike probabilities; in particular, positive ranks adequately represent belief and distinguish more or less firm beliefs (negative ranks correspondingly express disbelief). Moreover, in contrast to other theories of belief it can fully account for the dynamics of belief, a task equivalent to answering the problem of induction. The talk will explain some basic features and some surprising applications of ranking theory.