The basic unit of desirability in much decision theory, game theory, and economics. The difficulty is being sure that it refers to anything sufficiently definite to work with. This requires, for instance, that at least some comparisons of utility across different times and different people is possible. Stronger assumptions may require that utilities can be ordered in various scales, or summed and manipulated arithmetically (see felicific calculus ; measurement, philosophy of ). This may seem to involve a wild idealization, since although we might judge that this year's holiday was better than last year's, we are not apt to think it makes sense to say it was twice as good, or that it generated half as many units of utility as (say) a lifetime's consumption of chocolate. Cautious work prefers to use orderings of preferences: an outcome A has greater utility than outcome B (for subject x ) if and only if x prefers A to B. Preferences are in turn revealed in actual or idealized choices, thus allowing the concept some behavioural and scientific respectability. Again, however, most traditions of ethical thought recognize more valuable and worthwhile goals to life than simply satisfying an arbitrary sequence of preferences.
Philosophy dictionary. Academic. 2011.