 We haven’t given much of an argument for this rule, except that it “weighs” the desirability of each possible outcome against the probability that it will obtain. There are various ways one might develop this weighing idea, however. The one elaborated here is due to Savage (1954). It is considered the classic/orthodox approach in social sciences like economics and psychology. Philosophers, however, tend to prefer variations on Savage’s basic approach: either the “evidential” decision theory developed by Jeffrey (1965) or some form of  “causal” decision theory (see entry)  (Gibbard and Harper 1978; Skyrms 1980; Lewis 1981; Joyce 1999).