Lewis (1981) presented a version of causal decision theory that calculates expected utility using probabilities of dependency hypotheses instead of probabilities of subjunctive conditionals. A dependency hypothesis for an agent at a time is a maximally specific proposition about how the things the agent cares about do and do not depend causally on his present acts. An option’s expected utility is its probability-weighted average utility with respect to a partition of dependency hypotheses \(K_i\). Lewis defines the expected utility of an option \(A\) as