What exactly is the difference between act-utilitarianism and rule-utilitarianism? Can rule-utilitarianism succeed where act-utilitarianism fails?

Résumé du document

According to the meaning we give to ?actions', we get two different theories under Utilitarianism. And there is a great debate between those two schools of utilitarianism about how exactly the individual utilitarian should make his moral decisions.
The choice for the individual is between the principles of act-utilitarianism, which tells that the rightness or wrongness of a single action is to be judged by the action's consequences, and those of rule-utilitarianism, which tells that the action should be judged by a set of established rules, which are designed to produce the best consequences.
In this essay, I will first highlight the differences between act- and rule-utilitarianism, defining those two theories, before showing how they differ; then I will identify if rule-utilitarianism can succeed where act-utilitarianism has failed and identify objections made to each of them.

Extraits

[...] Most act- utilitarians are willing to agree as, as human beings we had no “infinite knowledge and clarity of thought and no partiality to self or other human weaknesses”[14]. Besides act- utilitarianism requires impartiality, which can be a difficult task, particularly when personal interests are involved in the calculation of utility. Indeed, suppose that a man is unhappily married and is deciding whether to get divorce. He will in all probability exaggerate his own unhappiness and underestimate the harm done to his children by the break up of the family.[15] As Hare puts it are very bad at putting ourselves in other people's shoes and imagining what it is like to be them”[16]. [...]

[...] In this case, even if there are plenty of problems with act- utilitarianism, one can wonder if rule- utilitarianism can really succeed as being the best utilitarianism form as act- utilitarianism appears as more flexible. Indeed act- utilitarians are able to recognize the advantages of generally relying on rules in the moral life without being caught up in the rule-worship that seems to characterize those who consider such rules to be absolute. As a conclusion and in the light of those arguments, it seems to me that though rule-utilitarianism appears to help us deal with many complaints related to act-utilitarianism, to strictly follow is equivalent to give up pure utilitarian principles in favour of sometime rule-worship, or instead have such a complete list of rules that in practise we have reverted to act- utilitarianism. [...]

[...] Hare, in Essays in Ehtical Theory (Oxford, 1989), The Structure of Ethics and Morals p 189 R.M. [...]

[...] Are there any critics made to rule- utilitarianism? Those are the questions I will try to answer in that last paragraph. Rule-utilitarianism invites us to consider the consequences of the general following of a particular rule. But following a rule in a particular case when the overall utility demands that we violate the rule is just rule- worship. Indeed if their rules are without exceptions, then rule utilitarians are rule-worshippers[18] according to act utilitarianism, as they say that we should follow the rule at any costs, even when it produces bad consequences. [...]

[...] If, in some particular situation, we have reason to question whether the rule-of-thumb will produce the best consequences, then it is entirely appropriate to call that rule-of-thumb into question in that instance. So an act utilitarian may accept the rule- of-thumb, “Don't but reconsider it in certain situation. Another problem with rule-utilitarianism is that the rule to follow to be correct would not be simple. Indeed, if we take the example of ought to tell the truth”, we can include it in the traditional rule-utilitarian code. But suppose one discovers a set of circumstances such as war- in which, lying would be more productive of utility than telling the truth. [...]