Published online by Cambridge University Press: 01 April 2022
One of us (Eells 1982) has defended traditional evidential decision theory against prima facie Newcomb counterexamples by assuming that a common cause forms a conjunctive fork with its joint effects. In this paper, the evidential theory is defended without this assumption. The suggested rationale shows that the theory's assumptions are not about the nature of causality, but about the nature of rational deliberation. These presuppositions are weak enough for the argument to count as a strong justification of the evidential theory.
The first author gratefully acknowledges grants from the American Council of Learned Societies and the Graduate School of the University of Wisconsin-Madison, and the second author is grateful to the latter institution and to the National Science Foundation.