Causal decision theory’s predetermination problem
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It has often been noted that there is some tension between engaging in decision-making and believing that one’s choices might be predetermined. The possibility that our choices are predetermined forces us to consider, in our decisions, act-state pairs which are inconsistent, and hence to which we cannot assign sensible utilities. But the reasoning which justifies two-boxing in Newcomb’s problem also justifies associating a non-zero causal probability with these inconsistent act-state pairs. Put together these undefined utilities and non-zero probabilities entail that expected utilities are undefined whenever it is a possibility that our choices are predetermined. There are three ways to solve the problem, but all of them suffer serious costs: always assume that, contrary to our evidence, the outcome of our present decision-making is not predetermined; give up the reasoning that justifies unconditional two-boxing in Newcomb’s problem; or allow epistemically impossible outcomes to contribute to expected utility, leading to the wrong results in a series of cases introduced by Ahmed (Br J Philos Sci 65(4):665–685, 2014a, Evidence, decision and causality, Cambridge University Press, Cambridge, 2014b). However they choose to respond, causal decision theorists cannot remain silent: the intuitive tension between decision-making and the possibility of predetermination can be made precise, and resolving it will require giving up something. Causal decision theorists have a predetermination problem.
KeywordsCausal decision theory Decision theory Determinism Predetermination Free will
This research was supported by an Australian Government Research Training Scheme Scholarship. Thanks to Al Hájek, Tim L. Williamson, Jeremy Strasser, Wolfgang Schwarz, Nevin Climenhaga, Alex Sandgren, and Edward Elliot for useful comments and discussion.
- Jeffrey, R. C. (1983). The logic of decision (2nd ed.). Chicago: University of Chicago Press.Google Scholar
- Lewis, D. (1973). Counterfactuals. Cambridge, MA: Harvard University Press.Google Scholar
- Pearl, J. (2000). Causality: Models, reasoning, and inference. Cambridge: Cambridge University Press.Google Scholar
- Savage, L. J. (1972). The foundations of statistics (2nd ed.). New York: Dover Publications.Google Scholar
- Sobel, J. (1994). Taking chances: Essays on rational choice. Cambridge studies in probability, induction, and decision theory. Cambridge: Cambridge University Press.Google Scholar