 The discussion in this section reviews the debate over whether the evaluation of legal rules and institutions should rely only on welfarist criteria. As noted earlier, Kaplow and Shavell [2001] offered an extensive argument for welfarism as the sole criterion. Their argument has several  elements.[29]  The first element identifies an individual’s well-being with her preferences. Thus, an individual K has greater well-being in state X than in state Y, if and only if she prefers state X to state Y. In the second, key element of the argument, welfarism interprets the agent’s preferences as her all-things-considered ranking of alternatives. This step thus incorporates within the agent’s preference ordering anything that the agent considers relevant to her decisions. Consequently, the claim about an agent’s well-being now becomes: K prefers state X to state Y if and only if K believes, all things considered, that state X is better than (or ought to be promoted rather than) state B. 