On the significance of conditional probabilities

The orthodoxy that conditional probabilities reflect what are for a subject evidential bearings is seconded. This significance suggests that there should be principles equating rationally revised probabilities on new information with probabilities reached by conditionalizing on this information. Several principles, two of which are endorsed, are considered. A book is made against a violator of these, and it is argued that there must be something wrong with a person against whom such books can be made. Appendices comment on Popper-functions, elaborate on bets and odds, and relate dutch books and strategies to conditions of inconsistency (Ramsey's idea) and imperfection.This paper corrects and elaborates two-fold Conditional Probabilities, Conditionalization, and Dutch Books, PSA 1990: Proceedings of the Biennial Meeting of the Philosophy of Science Association, Volume 1, edited by A. Fine, M. Forbes, and L. Wessels, East Lansing, Michigan, 1990.