I defend a general rule for updating beliefs that takes into account both the impact of new evidence and changes in the subject’s location. The rule combines standard conditioning with a “shifting” operation that moves the center of each doxastic possibility forward to the next point where information arrives. I show that well-known arguments for conditioning lead to this combination when centered information is taken into account. I also discuss how my proposal relates to other recent proposals, what results it delivers for puzzles like the Sleeping Beauty problem, and whether there are diachronic constraints on rational belief at all.
KeywordsBelief revision Update Conditionalisation Self-location Centered worlds
For helpful comments on earlier versions I would like to thank Jens Christian Bjerring, David Chalmers, John Cusbert, Alan Hájek, Namjoong Kim, Stephan Leuenberger, Weng Hong Tang, Michael Titelbaum, J. Robert G. Williams, two anonymous referees, and the audience of a PhilSoc seminar at the Australian National University in February 2008. Several points made in this paper, especially in Sect. 6, are also made in Meacham (2010), which appeared while this paper was under review.
- Arntzenius, F. (2003). Some problems for conditionalization and reflection. Journal of Philosophy, 100, 356–370.Google Scholar
- Feldman, R., & Conee, E. (1985). Evidentialism. Philosophical Studies, 48(1), 15–34.Google Scholar
- Halpern, J. (2006). Sleeping Beauty reconsidered: conditioning and reflection in asynchronous systems. In T. Gendler & J. Hawthorne (Eds.), Oxford studies in epistemology (Vol. 1, pp. 111–142). Oxford University Press.Google Scholar
- Jeffrey, R. (1983). The logic of decision (2nd ed.). Chicago: University of Chicago Press.Google Scholar
- Katsuno, H., & Mendelzon, A. (1991). On the difference between updating a knowledge database and revising it. In Proceedings of the 2nd international conference on principles of knowledge representation and reasoning (KR-92). pp. 387–394.Google Scholar
- Kumar, P. R., & Varaiya, P. (1986). Stochastic systems. Englewood Cliffs, NJ: Prentice-Hall.Google Scholar
- Lewis, D. (1999). Why conditionalize? In Papers in metaphysics and epistemology (pp. 403–407). Cambridge: Cambridge University Press.Google Scholar
- Meacham, C. (2010) Unravelling the tangled web: Continuity, internalism, non-uniqueness and self-locating beliefs. In T. S. Gendler & J. Hawthorne (Eds.), Oxford studies in epistemology (Vol. 3, pp. 86–125). Oxford University Press.Google Scholar
- Teller, P. (1973). Conditionalization and observation. Synthese, 26(2), 218–258.Google Scholar
- Vahid, H. (2004). Varieties of epistemic conservatism. Synthese, 141(1), 97–122.Google Scholar
- van Fraassen, B. (1999). Conditionalization, a new argument for. Topoi , 18(2), 93–96.Google Scholar