Jeremy Bentham, one of utilitarianism's early proponents, called the process of determining the most useful possible action the hedonistic calculus. One would, according to Bentham, measure the pleasure of certain actions against the pleasure of other actions. The problems of such a calculus include the feasibility of interpersonal utility comparisons, the weighting of utility through time, and the "artificial" utility gained not from actual actions but from, for example, avoiding risk. The theoretical person which nonetheless succeeds in undertaking such a computation is said to be a rational actor.
Utilitarianism and utility
"Utility" is defined as the good to be maximized. Different thinkers have further defined it as happiness, well-being or pleasure. The idea of utilitarianism as a moral code was first thought up by 18th century reformer and philosopher Jeremy Bentham. He believed that, "nature has put man under the governance of two sovereign masters: pleasure and pain." Thus, he concluded that good is whatever it is that brings on the greatest happiness. His belief was passed on by others after him.
Across the social sciences, utilitarianism is encountered in the form of rational choice theories. In economics, it is the foundation of marginal analysis. In these academic contexts, utilitarianism serves as a tool for the analysis of social behavior. The partial exception to this lies in the field of welfare economics, where some economists have tried to apply modern forms of the "hedonistic calculus" to issues of public choice.
Critiques of utilitarianism
Utility has been accused of supporting the idea that the ends justifies means, or that only material means count in the "hedonistic calculus." In fact, this is exactly what Bentham is arguing for.
In addition, Utilitarianism has been accused of being an unworkable system, since one cannot necessarily know the consequences of all actions.
Robert Nozick used the utility monster argument to demonstrate that the existence of something extremely efficient at turning resources into pleasure would justify large scale neglect of human needs and wants, potentially to the extent of obliging us to allow the human race to go extinct.
Nozick also used the analogy of The Experience Machine to demonstrate that people value something other than pleasure.
It has also been pointed out that Utilitarianism does not acknowledge special relationships, entitlements and agreements. For example, most people consider themselves justified in prioritising the well being of their friends and loved ones, even when more pleasure would be produced by aiding worse off strangers. People would also consider it unjust if their employer decided to give their paychecks to charity, because even though giving the paycheck to charity may service the greater good, the employee is entitled to his paycheck. An agreement like someone promising to do something for someone else could be broken for the greater good, but it is hard to see how this is justified except in extreme circumstances. The utilitarian counter-argument would be that breaking a promise or a contract generally causes unhappiness, and so it is wrong after all. A rule utilitarian would point out that while breaking a contract instead of keeping it may occasionally cause greater happiness in particular circumstances, consistently keeping contracts causes greater happiness than consistently breaking them, and thus one should follow the rule of keeping contracts.