in the 20th century Ideal utilitarianism The description of ideal utilitarianism was first used by Hastings Rashdall in The Theory of Good and Evil (1907), but it is more often associated with G. E. Moore. In Ethics (1912), Moore rejects a purely hedonistic utilitarianism and argues that there is a range of values that might be maximized. Moore's strategy was to show that it is intuitively implausible that pleasure is the sole measure of what is good. He says that such an assumption: Moore admits that it is impossible to prove the case either way, but he believed that it was intuitively obvious that even if the amount of pleasure stayed the same a world that contained such things as beauty and love would be a better world. He adds that, if a person was to take the contrary view, then "I think it is self-evident that he would be wrong." Act and rule utilitarianism In the mid-20th century, a number of philosophers focused on the place of rules in utilitarian thought. It was already accepted that it is necessary to use rules to help you choose the right action because the problems of calculating the consequences on each and every occasion would almost certainly result in you frequently choosing something less than the best course of action. Paley had justified the use of rules and Mill says: However, rule utilitarianism proposes a more central role for rules that was thought to rescue the theory from some of its more devastating criticisms, particularly problems to do with justice and promise keeping. Smart (1956) and McCloskey (1957) initially use the terms extreme and restricted utilitarianism but eventually settled on the prefixes act and rule instead. Likewise, throughout the 1950s and 1960s, articles were published both for and against the new form of utilitarianism, and through this debate the theory we now call rule utilitarianism was created. In an introduction to an anthology of these articles, the editor was able to say: "The development of this theory was a dialectical process of formulation, criticism, reply and reformulation; the record of this process well illustrates the co-operative development of a philosophical theory." The essential difference is in what determines whether or not an action is the right action. Act utilitarianism maintains that an action is right if it maximizes utility; rule utilitarianism maintains that an action is right if it conforms to a