Utilitarianism

Utilitarianism is the idea that we should do what has utility, or is beneficial. Classical utilitarianism, the most popular variety, defines utility as the welfare of all sentient beings.

Elements
Utilitarianism can be unpacked into three parts. Each of these can cause misunderstanding, which is addressed.
 * Consequentialism, or teleological ethics, states that value exists only in the consequences of acts. The major alternatives to consequentialism are virtue ethics and deontology (rule-based ethics).
 * Though “The end justifies the means” can describe consequentialism, the phrase is often interpreted in a way contrary to utilitarianism. It is commonly understood to entail disregard for the harmful side effects of pursuing a particular objective. But negative side-effects could make the action, on balance, harmful, which would betray the goal of utilitarianism. Instead, utilitarians take into account all of the effects of an action including side-effects.
 * Commensurability, or aggregation, is the principle that beneficial and detrimental effects of an action can be combined. By totaling, by averaging, or with any consistent system, a utilitarian can find the best course of action.
 * What commensurability does not mean is that the beneficial and detrimental effects of an action are always perfectly known, or that they need to be quantified precisely.
 * Impartiality means that the consequences of an action should be given equal consideration regardless of factors such as race, gender, sexual orientation, or species. The principle of impartiality distinguishes utilitarianism from egoism: the idea that only your own interests, not those of others, matter.
 * Impartiality does not, however, deny that there are differences between individuals or between groups of individuals. Some individuals are cleverer, taller, stronger, or more emotional than others. Utilitarians do not believe that such differences justify any partiality in the consideration of their interests.

Varieties
The following questions distinguish utilitarian theories:
 * What is utility?
 * Which events should have maximal utility?

Classical and Preference
Classical utilitarianism defines utility as the presence of happiness and the absence of suffering. Classical utilitarians locate value in their conscious inner lives. Preference utilitarianism defines utility as the satisfaction of preferences, or the consideration of all beings’ interests. Preferences are either internal (referring to one’s mind e.g. craving chocolate) or external (referring to the outside world e.g. wanting a new house). They can refer to the past, present or future. So it is the past, future and external preferences that distinguish preference utilitarians from classical ones.

Higher and Lower Pleasures
Higher pleasures include the intellectual satisfaction of learning and the satisfaction of plying a practiced skill. Lower pleasures are simpler, including eating and having sex. The ethical significance of this difference was controversially put by Mill: "It is better to be a human being dissatisfied than a pig satisfied; better to be Socrates dissatisfied than a fool satisfied. And if the fool, or the pig, are a different opinion, it is because they only know their own side of the question." . Critics accuse Mill of partiality to Socrates and divergence from utilitarianism.

Semantics of Classical Utilitarianism
John Stuart Mill has identified a problem with misunderstanding of pleasure. "“Every writer, from Epicurus to Bentham, who maintained the theory of utility, meant by it, not something to be contradistinguished from pleasure, but pleasure itself, together with exemption from pain; and instead of opposing the useful to the agreeable or the ornamental, have always declared that the useful means these, among other things. Yet the common herd [who hear the word utilitarian] habitually express by it the rejection, or the neglect, of pleasure in some of its forms; of beauty, of ornament, or of amusement. Nor is the term thus ignorantly misapplied solely in disparagement, but occasionally in compliment; as though it implied superiority to frivolity and the mere pleasures of the moment. And this perverted use is the only one in which the word is popularly known”" The challenge to find an inclusive term for value is ongoing. To non-philosophers today, the term “utility” excludes beauty, ornament and amusement. The term “pleasure” is restricted to its lower forms. The term “fulfillment” expresses disregard for the lower pleasures. While these terms are not synonyms, they can all refer to a feeling that is regarded valuable in and of itself.

Average and Total
Utilitarians can evaluate a world by either totaling or averaging utility. Imagine a world containing a hundred beings, each of whose lives had ten “hedons”, or units of wellbeing. Contrast this with a world with a world of twenty beings, whose lives have twenty hedons each. Which world is better? A total utilitarian would favour the former world. This more populated world would “win” with one thousand hedons to four hundred. According to an averaging utilitarian, however, the latter world would “win”, with twenty hedons to ten. Derek Parfit has highlighted this difference. In his Repugnant Conclusion, total utilitarianism questionably favours a large number of people with extremely little utility over a moderate population living in comfort.

The averaging / totalling distinction applies to decisions at the beginning of life, such as in vitro fertilisation, and the end of life, including the withdrawal of life support.

Negative Utility
Utilitarians variously evaluate positive and negative utility:
 * To a positive utilitarian, happiness is good. A world with no happiness has zero value.
 * In the symmetrical view, happiness and suffering are weighed against each other. A world with equal happiness and suffering has zero value.
 * To the negative utilitarian, suffering is bad. A world with no suffering has zero value.

Maximising and Scalar
A maximizing view regards the most beneficial act (or event) to be right, while other acts are wrong. A scalar utilitarian view regards acts to be never absolutely right or absolutely wrong. Instead, they are only better or worse in proportion to their benefit.

Which Events Should Have Maximal Utility? (Evaluation Focus)

 * Act utilitarianism tells us to evaluate each act according to its utility and select the act with the highest expected utility.
 * Rule utilitarianism tells us to set the most beneficial set of rules according to their expected utility, and to adhere to them. Actions are considered good if they conform to the optimal set of rules.
 * Two-level utilitarianism, pioneered by R M Hare, says that we should act like a rule utilitarian on a day-to-day basis, but when an important decision arises, one should resolve conflict between rules by deliberating like an act utilitarian.
 * Global utilitarianism, is explained by Toby Ord: Where act-consequentialism  assesses  acts  in  terms  of  their consequences, global consequentialism goes much  further, assessing acts, rules, motives —  and  everything  else  —  in  terms  of  the  relevant  consequences. Compared to  act-consequentialism it offers  a number of  advantages: it is more expressive,  it  is  a  simpler theory,  and it  captures  some  of  the  benefits  of  rule consequentialism without the corresponding drawbacks.

Unifying Principle
Consequentialism, which includes utilitarianism, stands in contrast to ethical systems that assert that morality is defined by a collection of ethical principles that are not unified (see Ethical Pluralism). The unifying principle of utilitarianism is the principle of utility (see also Principles of Morals and Legislation). One advantage of moral systems that describe a unifying principle is that they provide a mechanism through which ethical conflicts might be resolved. For example, if two proposed actions are being considered (say building a bridge or using the same money to build an addition to a hospital), utilitarianism offers a theoretical basis for deciding which action is preferable. Estimated utility would constitute the decision criteria (although pragmatically the decision would be challenging). Other ethical systems, such as deontological ethics and virtue ethics, propose long lists of ethical principles, most of which lack a natural hierarchy or any other legitimate basis that would allow adherents to resolve conflicts.