Mill attempts to reply to misconceptions about utilitarianism, and thereby delineate the theory. Mill observes that many people misunderstand utilitarianism by interpreting utility as in opposition to pleasure. In reality, utility is defined as pleasure itself, and the absence of pain. Thus another name for utility is the Greatest Happiness Principle. This principle holds that "actions are right in proportion as they tend to promote happiness, wrong as they tend to produce the reverse of happiness. By happiness is intended pleasure, and the absence of pain; by unhappiness, pain, and the privation of pleasure." Pleasure and the absence of pain are, by this account, the only things desirable as ends in themselves, the only things inherently "good." Thus, any other circumstance, event, or experience is desirable only insofar as it is a source for such pleasure; actions are good when they lead to a higher level of general happiness, and bad when they decrease that level.
The next criticism Mill takes on is the claim that it is base and demeaning to reduce the meaning of life to pleasure. To this Mill replies that human pleasures are much superior animalistic ones: once people are made aware of their higher faculties, they will never be happy to leave them uncultivated; thus happiness is a sign that we are exercising our higher faculties. It is true that some pleasures may be "base"; however, this does not mean that all of them are: rather, some are intrinsically more valuable than others. When making a moral judgment on an action, utilitarianism thus takes into account not just the quantity, but also the quality of the pleasures resulting from it.
Mill delineates how to differentiate between higher- and lower-quality pleasures: A pleasure is of higher quality if people would choose it over a different pleasure even if it is accompanied by discomfort, and if they would not trade it for a greater amount of the other pleasure. Moreover, Mill contends, it is an "unquestionable fact" that, given equal access to all kinds of pleasures, people will prefer those that appeal to their "higher" faculties. A person will not choose to become an animal, an educated person will not choose to become ignorant, and so on. Even though a person who uses higher faculties often suffers more in life (hence the common dictum "ignorance is bliss"), he would never choose a lower existence, preferring instead to maintain his dignity.
Another misconception about utilitarianism stems from a confusion of happiness with contentment. People who employ higher faculties are often less content, because they have a deeper sense of the limitations of the world. However, their pleasure is of a higher character than that of an animal or a base human. Mill writes, "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 of a different opinions, it is because they only know their side of the question." Thus the people best qualified to judge a pleasure's quality are people who have experienced both the higher and the lower.
Furthermore, Mill observes that even if the possession of a "noble character" brought less happiness to the individual, society would still benefit. Thus, because the greatest happiness principle considers the total amount of happiness, a noble character, even if it is less desirable for the individual, is still desirable by a utilitarian standard.
This chapter provides the definition of utilitarianism. There are a few important aspects of this definition. First, it presents utility, or the existence of pleasure and the absence of pain, as both the basis of everything that people desire, and as the foundation of morality. However, utilitarianism does not say that it is moral for people simply to pursue what makes them personally happy. Rather, morality is dictated by the greatest happiness principle; moral action is that which increases the total amount of utility in the world. Pursuing one's own happiness at the expense of social happiness would not be moral under this framework.