A Nonpragmatic Vindication of Probabilism
Published online by Cambridge University Press: 01 April 2022
The pragmatic character of the Dutch book argument makes it unsuitable as an “epistemic” justification for the fundamental probabilist dogma that rational partial beliefs must conform to the axioms of probability. To secure an appropriately epistemic justification for this conclusion, one must explain what it means for a system of partial beliefs to accurately represent the state of the world, and then show that partial beliefs that violate the laws of probability are invariably less accurate than they could be otherwise. The first task can be accomplished once we realize that the accuracy of systems of partial beliefs can be measured on a gradational scale that satisfies a small set of formal constraints, each of which has a sound epistemic motivation. When accuracy is measured in this way it can be shown that any system of degrees of belief that violates the axioms of probability can be replaced by an alternative system that obeys the axioms and yet is more accurate in every possible world. Since epistemically rational agents must strive to hold accurate beliefs, this establishes conformity with the axioms of probability as a norm of epistemic rationality whatever its prudential merits or defects might be.
- Research Article
- Copyright © Philosophy of Science Association 1998
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I have been helped and encouraged in the development of these ideas by Brad Armendt, Robert Batterman, Alan Code, David Christensen, Dan Farrell, Allan Gibbard, Alan Hajek, William Harper, Sally Haslanger, Mark Kaplan, Jeff Kasser, Louis Loeb, Gerhard Nuffer, Peter Railton, Gideon Rosen, Larry Sklar, Brian Skyrms, Bas van Fraassen, David Velleman, Peter Vranas, Nick White, Mark Wilson, Steve Yablo, and Lyle Zynda. Richard Jeffrey's influence on my thinking will be clear to anyone who knows his writings. Special thanks are also due to two anonymous referees from Philosophy of Science, whose splendidly detailed comments greatly improved the final version of this paper.