The central aim of John Stuart Mill’s Utilitarianism is to defend the view that those acts that produce the greatest happiness of the greatest number of people are right and good. This ethical position did not originate with Mill. An influential predecessor, Jeremy Bentham, earlier championed pleasure and pain as the sole criteria for judging what is good and bad. The utility yardstick measures good by asking: Does an act increase pleasure, and does it decrease pain? Bentham’s crude “Push-pin is as good as poetry” interpretation of the yardstick led to numerous criticisms. Therefore, Mill states the principle of utility in its most defensible form both to counter some specific criticisms of it and to make clear what the sanctions of the principle are. He also offers a proof of the principle. The work concludes with a discussion of the relation of utility to justice.

Utilitarianism opens with the author’s lament that little progress has occurred through centuries of ethical analysis. Ethical philosophers seeking to define the nature of “good” have left a number of incompatible views to their intellectual posterity. Mill admits that history of scientific thought also contains confusion about the first principles of the special sciences. Yet this is more to be expected in the sciences than in moral philosophy. Legislation and morals involve practical rather than theoretical arts. Because such arts always aim at ends of action rather than thought, they require agreement about a standard by which the worth of those ends can be evaluated. There is greater need of fixing the foundation of morals than of stating the theoretical principles underlying bodies of scientific knowledge. The sciences result from accumulation of many particular truths, but in moral philosophy “A test of right and wrong must be the means, one would think, of ascertaining what is right or wrong, and not a consequence of having already ascertained it.”

Ethical intuitionists insist that people possess a natural faculty that discerns moral principles. Against them, Mill argues that appeal to a “moral sense” cannot solve the problem of an ultimate ethical standard for judging acts. No intuitionist claim about knowledge of moral principles can provide a basis for decisions regarding cases. Intuitionist and inductive moral theorists usually disagree about the “evidence and source” grounding moral principles. Clearly, then, the main problem facing moral philosophers is that of justifying their judgments in the light of a defensible principle.

Mill asserts that even those philosophers who wish to reject the greatest-happiness principle must invoke it. For example, the German philosopher Immanuel Kant claimed that the basis of moral obligation involves a categorical imperative: “So act that the rule on which thou actest would admit of being adopted as a law of all rational beings.” Mill insists that numerous, even contradictory, notions of duties can follow from this imperative. Kant’s noble effort thus leads to decisions that can be shown to be immoral only because the consequences of some universally adopted acts would be unwanted by most people.

The fact that people tacitly employ the utility yardstick is not the same as a proof of its validity. Mill offers to present such a proof. He makes clear that no absolutely binding proof, “in the ordinary and popular meaning of the term,” is possible. To give a philosophical proof means to advance reasons directed at one’s rational capacities. Philosophical proofs are their own kinds of proofs. It is in this sense of proof that Mill promises to make good after he has first more fully characterized the utilitarian doctrine.

Mill must first perform an important polemical function in replying to critics who have problems with the utilitarian doctrine. The polemic is to serve the persuasive goal of winning over critics to a proper understanding of utilitarianism, whose basic view of life is “that pleasure and freedom from pain are the only things desirable as ends.” A corollary to this claim is that all things desirable are so either for the pleasure they can directly produce or for ways in which they serve as means to other pleasures or preventions of pain. Aware that some thinkers view his idea as a base moral conception, Mill states a number of outstanding objections to it. He argues that the objections represent either misunderstandings of the utilitarian doctrine or, if they contain some truth, views that are not incompatible with it.

Mill rejects the argument that utilitarianism chooses to picture human nature at the lowest animal level. Clearly, animals are incapable of experiencing many pleasures available and important to people. Every “Epicurean theory of life” also admits that intellectual pleasures are more valuable than those of simple sensation. “It is quite compatible with the principle of utility to recognize the fact that some kinds of pleasure are more desirable and more valuable than others.” Pleasures must be judged in terms of quality as well as quantity. Mill suggests a way in which the value of two possible pleasures may be determined. Only that person who, out of wide experience, knows both pleasures can decide and can thus state a comparative judgment. Apparently Mill believed this test is adequate. He assumed that the experienced person actually knows the worth of competing pleasures in a manner that is not simply psychological but objective. Rational beings should choose pleasures of higher quality. Not all people are equally competent to render decisive judgments. In a striking sentence Mill writes: “It is better to be a human being dissatisfied than a pig satisfied.”

In Utilitarianism, Mill replied to a number of other important criticisms of the utilitarian doctrine.

First, the utilitarian greatest-happiness principle is said to be too exalted in expecting human beings to adopt a disinterested moral posture. Mill’s reply is that in serving the interests of one’s fellow creatures, the motive may be either self-interest or duty. The resulting act rather than the motive must be judged, though the motive of duty can influence people to honor the character of the doer as well. People can promote the general interests of society without always fixing “their minds upon so wide a generality as the world, or society at large.”

Second, to the charge that utilitarianism will make people cold and unsympathizing, Mill answers that people should show interest in things other than those concerned with standards of right and wrong. Yet it is necessary to emphasize the need of making judgments of right and wrong and to supply moral standards for human behavior.

Third, Mill calls simply false the view that utilitarianism is a godless doctrine. Religiously inclined people can use the utilitarian standard to determine what in detail the will of God means for human action.

Fourth, some critics complain that utilitarianism will end in expediency. Mill’s rebuttal is that the utility principle does not justify acts that result only in the pleasure of the lone individual. The social standard must always operate.

Fifth, Mill argues that utilitarianism can account even for the actions of martyrs and heroes. Heroism and martyrdom involve individual sacrifices whose ultimate aim is an increase in the happiness of others or of society as a whole.

Other criticisms—that utilitarianism overlooks lack of time for people to decide the results of given actions and that utilitarians may use the doctrine to exempt themselves from moral rules—are shown to apply equally to other ethical doctrines.

Mill goes on to admit that other questions about a moral standard can be raised. For what reasons should any person adopt the standard? What motivates one to apply it? There are two possible kinds of sanctions for utilitarianism—external and internal sanctions. Desire of favor and fear of displeasure from one’s fellows or from a sovereign God constitute the utilitarian principle’s external sanctions. Given feelings of affection for other people or awe for a God, people may act also out of unselfish motives that can “attach themselves to the Utilitarian morality, as completely and powerfully as to any other.”

Conscience makes up the internal sanction of the principle. Mill defines conscience as “a pain, more or less intense, attendant on violation of duty.” This sanction is really a feeling in the mind such that any violation of it results in discomfort. Even those who think moral obligation has roots in a transcendental sphere act conscientiously only insofar as they harbor religious feelings about duty. There must be a subjective feeling of obligation. However, is this feeling of duty acquired or innate? If innate, the problem concerns the objects of the feeling. Intuitionists admit that principles rather than the details of morality get intuited. Mill argues that the utilitarian emphasis on regard for the pleasures and pains of others might well be an intuitively known principle. Some regard for interests of others is seen as obligatory even by intuitionists who insist on yet other obligatory principles. Mill thought that any sanction provided by a transcendental view of the origin of obligation is available to the utilitarian doctrine.

Nevertheless, Mill’s view was that people’s notions of obligation are actually acquired. Though not a part of human nature, the moral faculty is an outgrowth of it. This faculty can arise spontaneously in some circumstances as well as benefit from proper environmental cultivation. The social feelings of humankind provide a basis of natural sentiment that supports the utilitarian doctrine. “Society between equals can only exist on the understanding that the interests of all are to be regarded equally.” Proper education and social arrangements can encourage the moral feelings toward virtuous activity. By education, people can learn to value objects disinterestedly which, in the beginning, they sought only for the sake of pleasure. Mill claims that virtue is one good of this kind.

In Utilitarianism, Mill raises a question as to whether the utility principle can be proved. It is difficult to understand what kind of question Mill thought he was asking. The setting for this question appears to involve something like the following: When someone asks if the principle has any sanctions, it is as if he were to ask, “Why should I seek the good even if the utility principle is sound?” However, when someone asks for a proof of the principle, it is as if he were to inquire, “How can I know that the utility principle is true?” Strangely, this question comes up only after Mill has already refuted a whole range of criticisms of the utilitarian doctrine as well as shown the sanctions that support it.

Mill argues that “the sole evidence it is possible to produce that anything is desirable, is that people do actually desire it.” One difficulty with this assertion concerns the word “sole.” Even if it is true that nothing can be desirable that is not desired by someone, would it follow necessarily that one’s desire of an object is sufficient evidence of its desirability? If not, what besides desire would account for an object’s desirability? Contextually, it would appear that Mill might have to agree that though everything desirable must be desired, not everything desired need be desirable. This would follow from his earlier claim that some pleasures are qualitatively better than others. A human being who desired to live like a pig would seek to evade realizing the highest kind of happiness available to him or her. To this argument, Mill might have wanted to reply that, in fact, no one really does want to live like a pig. Yet the most controversial aspect of Mill’s proof occurs when he insists that “each man’s happiness is a good to that person, and the general happiness, therefore, a good to the aggregate of all persons.” Some philosophers call this statement an example of an elementary logical fallacy—attribution of a property applicable to the parts of a collection to the collection itself. The utilitarian stress on people’s obligation to seek the happiness of the greatest number raises a question about the relation of individual pleasures to social ones. A person may desire to drive at high speeds as an individual, yet not have grounds for making desirable the changing of the speed rules. What Mill wants to emphasize is that in conflicts between social and individual interests, the individual interests must often give way.

Ultimately a conception of human nature must serve as justification for Mill’s use of the utility principle. The proof runs to the effect that people are, after all, naturally like that. If they do not seek happiness directly, they seek other ends as a means to it. To a skeptic convinced that the principle cannot be proved by an appeal to human nature, Mill might have said: “Obviously, you misunderstand what you really desire.” In this case, the utility principle is proved in that it conforms to what people are like. On this basis, however, it seems peculiar to want to argue that people ought to use the principle in making moral judgments. To say that people ought to act in a given way is to imply that they may not.

The concluding chapter of Utilitarianism discusses the relation of justice to utility. The idea of justice tends to impede the victory of the utilitarian doctrine, according to Mill. People’s sentiment of justice seems to suggest existence of a natural, objective norm that is totally divorced from expediency and hedonistic consequences. Mill’s task was to indicate how the utilitarian doctrine could accommodate this sentiment and nevertheless remain the sole acceptable standard for judging right and wrong.

One must examine objects in the concrete if one wants to discover whatever common features they may contain. This is true of the idea of justice. Several fundamental beliefs are associated in popular opinion with notions such as “just” and “unjust.” Justice involves respect for the legal and moral rights of other people. It implies the wrongfulness of taking away another’s moral rights by illegal or even legal means. There can be bad laws. The notion of desert is also important. This notion entails belief that wrongdoing deserves punishment and the doing of right deserves reciprocation in good acts. Justice cannot mean doing good in return for evil, according to Mill. Nevertheless, people may waive justice when they are wronged. Furthermore, people ought not to break promises that are willingly and knowingly made. This is so even in the case of implied promises. Justice precludes a breach of faith. Finally, justice implies impartiality and equality in the treatment of people and claims. This means that people ought to be “influenced by the considerations which it is supposed ought to influence the particular case in hand.” Mill concludes that several general features rather than one are common to these opinions about justice. Turning to the etymology of the word, he asserts that the primitive meaning of justice is “conformity to law.” The Greeks and Romans, recognizing the possibility of bad laws, came to view injustice as the breaking of those laws that ought to be obeyed. The idea of justice in personal conduct also involves the belief that a person ought to be forced to do just acts.

To say that justice accepts the idea of the desirability of compelling people to do their duty tells people what justice is about. Yet it does not distinguish justice from other branches of morality. According to Mill, justice involves the notion of perfect obligation. Duties of perfect obligation imply the existence of a correlative right in a person or persons. “Justice implies something which it is not only right to do, and wrong not to do, but which some individual person can claim from me as his moral right.” This view of justice admits a distinction between moral obligation and the domains of beneficence and generosity. In people, the sentiment of justice becomes “moralized,” spread over a social group or community. Justice then involves the feeling that one ought to punish those who harm members of that community. People’s need of security plays a role here as does the idea of right. Justice involves a belief that there are rights that morally society must defend. Thus justice is compatible with the utility principle, for “when moralized by the social feeling, it only acts in directions conformable to the general good.”

The idea of justice requires belief in a rule of conduct applicable to all people, plus a sentiment that sanctions the rule. This sentiment, which insists that transgressors be punished, is compatible with the utility principle if the idea of justice is taken to refer to special classes of moral rules. These are the rules without which the realization of the general good would be impossible. An important example of such rules would be those forbidding one person to harm another. Such rules presuppose the utilitarian doctrine that one person’s happiness must be considered as important as another’s. Mill’s conclusion is that “Justice remains the appropriate name for certain social utilities which are vastly more important, and therefore more absolute and imperative, than any others are as a class.”

Utilitarianism is a book of significance for thinkers concerned about the problem of moral fairness in a social setting. Mill attempted to show that people’s notions of obligation can be made compatible with the utility principle. What animates the work is Mill’s clear conviction that even the more exalted moral claims of intuitionists and Kantian moralists make sense only if the utilitarian doctrine is the true one. Only with justice and binding rules of obligation can people achieve the greatest happiness of the greatest number.