A philosophy cannot be binding if it does not contain inherent consequences for those who break its rules. In this chapter, Mill says he will explore what built-in sanctions utilitarianism can provide; in other words, what punishments the philosophy might impose upon those who do not abide by it. Mill notes a potential challenge to the utilitarian system: if a person is presented with a first principle that general custom does not deem fundamental, that person will see no reason to respect or value that principle. Rather, the corollary moral ideas based on the first principle will seem to have a stronger foundation (because they enjoy general acceptance) than the foundation itself. Mill says that this challenge will simply persist for utilitarianism until education influences people to see the general good as a deeply rooted moral good. Until this occurs, however, the problem is not unique to utilitarianism, but is rather inherent to any system that attempts to find foundations for morality.
Mill writes that utilitarianism has or can impose all the sanctions that other moral systems can. Mill notes that there exist both external and internal sanctions: external sanctions exist externally to the human agent as an individual; they may take the form of peer pressure—the fear of their disapproval—or of divine pressure—the fear of his wrath. Mill argues that these motives could just as easily be associated with utilitarianism as with any other moral system. The second type of sanction, internal sanctions, stems from one's conscience; these consist of feelings in one's own mind that create discomfort when one violates duty. These feelings can influence actions, if one's moral nature has been sufficiently cultivated. Indeed, internal sanctions are more powerful than any external sanction. And, as they are a fact of human nature, there is no reason to think that they can't be cultivated to support utilitarian principles in specific.
Mill acknowledges that many people believe that individuals are more likely to follow moral principles if they see them as objective fact, rather than if they see them as rooted in subjective feelings. However, Mill observes that whatever a person believes the root of a moral principle to be, his ultimate motivation to action is always subjective feeling. Furthermore, the problem of people ignoring their consciences is a problem facing all of humanity, not just the philosophy of utilitarianism.
Thus, if internal sanctions provide the strongest influence over people's actions, utilitarianism must appeal to people's inner sentiments in order to exercise a binding force on them. Mill addresses the issue of whether the sentiment of duty is "innate or implanted" in human consciousness by saying that for the purposes of this essay, the distinction is not important, because either way it would support utilitarianism. Mill maintains that moral feelings are acquired; however, this does not mean that they are not natural. Moral feelings may not be a part of human nature, but they are a natural outgrowth of it. They can spring up to some degree spontaneously, but they can also be cultivated. However, bad moral principles can also be cultivated in people, under the pressure of external sanctions. These are "artificial" moral feelings, because they are imposed rather than naturally developed. However, we can distinguish these from natural moral feelings because the artificial ones eventually dissolve under scrutiny of analysis. Now, because the feeling of duty crucial to utilitarianism does not crumble under reflection, utility emerges as a particularly strong foundation. This suggests that there is "a natural basis of sentiment for utilitarian morality."
Thus, Mill argues that once general happiness becomes recognized as the moral standard, natural sentiment will nurture feelings that promote utilitarianism. Mill argues that utilitarianism thus has its roots in the social nature of human beings—in their desire to be in unity with other humans, and their fear of other people's disapproval. Society can harbor no relations other than the master-slave relationship unless it has as its base the principle that all people's interests have equal merit. Because society is currently advancing towards equality, people grow up seeing it as impossible to wholly disregard other people's interests. Mill argues that society could and should nourish this natural sentiment through education and law. He asserts that if we imagine that this feeling of social unity were taught in the same way religion is taught, and thus implanted as an internal sanction, then utilitarianism would exert a binding force sufficient to influence behavior. Furthermore, this feeling does not require the education system just described in order to be able to influence people; for even in this comparatively early state of advancement, people cannot escape feeling a degree of fellow-feeling with other humans. This sentiment is usually eclipsed by selfish feelings, but for those who have it, it does take on the character and legitimacy of a natural feeling. Thus, utilitarianism's sanctions are based on natural human sentiments, which the proper system of education could nurture.
Mill's discussion about sanctions is quite abstract, and it might be clearer if illustrated with an example. Imagine that a philosopher poses a moral theory that declares that actions are morally good insofar as they promote human suffering. Now, one issue for any moral theory is that people must be capable of internalizing its dictates. In this case, it must be possible for a person's conscience to sting him if he failed to make others suffer. Is it possible for people to feel that causing suffering is morally good? Mill would say that it is possible: people could be educated and socialized in such a way that they have internal sanctions that promote suffering. However, Mill would argue that such feelings would be artificial: they are not based on human nature, or on facts of human experience. Rather, they come closer to being the result of brainwashing. As a result, if people analyzed or reflected on their sentiments, they would come to reject this theory of suffering. For what is a true fact of human nature is the inclination to work together socially, to share in each other's endeavors—and to make other suffer is a behavior that contradicts that fact.
Mill would argue that unlike such a hypothetical system, utilitarianism accommodates these facts about human nature. This does not mean that all people have feelings that support the rules of utilitarianism; they may have been socialized to value other things. Mill's point, however, is that if people were educated to embrace utilitarianism, they would develop a sentiment promoting social utility as morally good. Such a sentiment would make people feel guilty if they worked against utilitarian ends. Furthermore, such a sentiment would not be rejected upon reflection, as would a social system based on suffering. Rather, since utilitarian sentiments are natural, they harmonize with human nature and make sense upon reflection.
Why is it so important for Mill to show that utilitarianism would be supported by people's sentiments? Mill believes that any moral theory must be capable of binding people to its dictates. He tries to show that the only way that people are bound, however, is through how they feel. Thus, in order for utilitarianism to be tenable as a theory, people must be able to feel that promoting general happiness is a morally good thing. Mill is attempting to show that utilitarianism does fulfill this requirement. One thing worth considering here, is whether a person could have a logical or intellectual reason to do something even if his sentiments did not support doing so. Mill assumes that this is not possible. But might human beings' actions be motivated by influences other than their sentiments? How might Mill reply to this concern? A second question: Can moral principles hold sway in society without the kind of enforcement mechanism Mill believes is required?