 A related criticism of Rawls’s “thick” veil of ignorance is that even if the parties can make certain rational decisions in their interest without knowledge of their final ends, still they cannot come to a decision about principles of justice. For justice consists, allegedly, of the measures that effectively promote good consequences. Without knowledge what is ultimately good (however that is to be defined) the parties cannot discover the principles of justice that best promote it. This criticism is mirrored in utilitarian versions of the moral point of view, which incorporate a “thin” veil of ignorance that represents a different idea of impartiality. The impartial sympathetic spectator found in David Hume and Adam Smith, or the self-interested rational chooser in John Harsanyi’s average utilitarian account, all have complete knowledge of everyone’s desires, interests and purposes as well as knowledge of particular facts about people and their historical situations. Impartiality is achieved by depriving the impartial observer or rational chooser of any knowledge of its own identity. This leads it to give equal consideration to everyone’s desires and interests, and impartially take everyone’s desires and interests into account. Since rationality is presumed to involve maximizing something – or taking the most effective means to promote the greatest realization of one’s ends – the impartial observer/chooser rationally chooses the rule or course of action that maximizes the satisfaction of desires, or utility (aggregate or average), summed across all persons. 