Causal Decision Theory is Safe from Psychopaths

Abstract

Until recently, many philosophers (and non-philosophers) took Causal Decision Theory (CDT) to be more successful than its rival, Evidential Decision Theory (EDT). Things have changed, however, with a renewed concern that cases involving an extreme form of decision instability are counterexamples to CDT (Richter in Austral J Philos 62(4):392–403, 1984; Egan in Philos Rev 116(1):93–114, 2007). Most prominent among those cases of extreme decision instability is the Psychopath Button, due to Andy Egan; in that case, CDT recommends a seemingly absurd act that almost certainly results in your death. This renewed attention to decision instability has spurned an array of modifications to and rejections of CDT. I argue, however, that the Psychopath Button and its ilk are no counterexamples to CDT. That is, given the causalist’s commitments in Newcomb Problems, they already have the tools to justify CDT’s verdict in Egan-style cases of extreme decision instability. I first argue that there is no reason to think the Psychopath Button is a counterexample to CDT; in particular, (1) many philosophers have placed too much weight on pre-theoretic intuition in Egan-cases, and (2) apart from pre-theoretic intuition, arguments against CDT in cases of extreme decision instability are flawed. My second claim is that the causalist can provide good reasons for following CDT in cases of extreme decision instability. I present a new case, the Two Button Defense, that highlights precisely why the causalist can reasonably follow CDT in even the Psychopath Button. CDT therefore stands as a viable decision theory, without need for modification, restriction, or rejection.