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?