Having responded to the objection that utilitarianism glorifies base pleasures, Mill spends the rest of this chapter presenting and responding to other criticisms of utilitarianism.
One such objection is that happiness couldn't be the rational aim of human life, because it is unattainable. Furthermore, people can exist without happiness, and all virtuous people have become virtuous by renouncing happiness.
First, Mill replies that it is an exaggeration to state that people cannot be happy. He contends that happiness, when defined as moments of rapture occurring in a life troubled by few pains, is indeed possible, and would be possible for almost everybody if educational and social arrangements were different. The major sources of unhappiness are selfishness and a lack of mental cultivation. Thus, it is fully within most people's capabilities to be happy, if their education nurtures the appropriate values. Furthermore, most of the evils of the world, including poverty and disease, can be alleviated by a wise and energetic society devoted to their elimination.
Next, Mill addresses the argument that the most virtuous people in history are those who have renounced happiness. He admits this is true, and he admits that there are martyrs who give up their happiness. However, Mill argues that martyrs must sacrifice happiness for some greater end--and what else could this be but the happiness of other people? The sacrifice is made so that others will not have to make similar sacrifices; implicit in the sacrifice is the value of others' happiness. Mill admits that the willingness to sacrifice one's happiness for that of others is the highest virtue. Furthermore, he says that to maintain an attitude of such willingness is actually the best chance of gaining happiness, because it will lead a person to be tranquil about his life and prospects. He specifies, however, that while utilitarians value sacrificing one's good for the good of others, they do not think that the sacrifice is in itself a good. It is a good insofar as it promotes happiness, but is not a good if it does not promote happiness.
Mill observes that the utilitarian's standard for judging an act is the happiness of all people, not of the agent alone. Thus, a person must not value his own happiness over the happiness of others; and law and education help to instill this generosity in individuals. However, this does not mean that people's motives must only be to serve the greatest good; indeed, utilitarianism is not concerned with the motives behind an action; the morality of an action depends on the goodness of its result only. Moreover, in most aspects of everyday life, a person will not be affecting large numbers of other people, and thus need not consider his or her actions in relation to the good of all, but only to the good of those involved. It is only the people who work in the public sphere and affect many other people who must think about public utility on a regular basis.
Another criticism of utilitarianism is that it leaves people "cold and unsympathizing," as it is concerned solely with the consequences of people's actions, and not on the individuals as moral or immoral in themselves. First, Mill replies that if the criticism is that utilitarianism does not let the rightness or wrongness of an action be affected by the kind of person who performs the action, then this is a criticism of all morality: All ethical standards judge actions in themselves, without considering the morality of those who performed them. However, he says that if the criticism is meant to imply that many utilitarians look on utilitarianism as an exclusive standard of morality, and fail to appreciate other desirable "beauties of character," then this is a valid critique of many utilitarians. He says that it is a mistake to only cultivate moral feelings, to the exclusion of the sympathies or artistic understandings, a mistake moralists of all persuasions often make. However, he does say that if there is to be a mistake of priorities, it is preferable to err on the side of moral thinking.
In the first part of Chapter II, Mill responds to the major arguments against utilitarianism. In so doing, he carves out the nuances of his own brand of utilitarianism, such that this chapter may be read both as him defending the existing notion of utilitarianism (particularly the greatest happiness principle) and breaking with its earlier adherents (e.g. Jeremy Bentham).
Mill first devotes a passage to answering what he believes is an objection to utilitarianism formed out of simple ignorance: the argument that utility is in some way a concept divorced from pleasure. Mill sees this as nothing but lack of education on the part of the objectors, because utility is conceptualized exactly as a calculus of pleasure, and nothing else. He supposes that the misconception may have come from people simply hearing the word "utility" and intuiting from its sound that it was something cold and antithetical to matters of pleasure.
This prompts Mill to clearly articulate the central tenet of utilitarian philosophy, which he refers to as the greatest happiness principle. This principle defines the moral content of actions in proportion to their tendency to promote pleasure and mitigate pain, or vice-versa. So, an action that frustrates pleasure or induces pain is morally wrong, and an action that promotes pleasure or mitigates pain is morally right.
At this point, Mill references the older hedonic philosophies associated with Epicurus, and considers the charge that they pervert human nature by reducing it solely to the seeking of pleasure. Mill contends that this critique rests on the faulty premise that human beings are capable of pleasures no greater than the pleasures experienced by animals. When the full scope of human pleasure is encompassed, Mill argues, then the greatest happiness principle appears self-evident.
Yet Mill believes that there is another issue raised by the misguided critique of Epicureanism: the fact that pleasures are only differentiated by degree and duration. This problem is not resolved by simply considering the full range of human pleasures, for human beings would then still be in the same class as lower animals; they would merely be able to feel their pleasures more intensely, or for a longer period of time. This is an issue that Mill admits is merited and is apparent in the philosophies of utilitarianism that came before him - particularly those of Jeremy Bentham.
To resolves this issue, Mill makes a major break with previous utilitarian philosophy by arguing that there are fundamentally different kinds of pleasure. In Mill's account, animal pleasures are lesser than human pleasures of the intellect, thereby creating a qualitative difference that morally divides humans and animals. In so doing, Mill assuages the worry that utilitarianism robs humans of the virtue of their faculties of reason.
There are two main, noteworthy moves made by Mill in drawing his conclusion about the different types of pleasure. First, he submits that the relative value of different pleasures is determined by the consensus of people who have experienced all pleasures considered. He then says that people who have experienced both animalistic pleasures and intellectual pleasures almost unanimously prefer the latter regardless of duration or intensity, and that this gives us reason to believe that they constitute a different kind of pleasure altogether.
Something Mill could be pressed on today is whether or not humans really are a separate moral class than animals. In some sense, the distinction Mill felt compelled to draw is an artifact of his time; no one, much less philosophers, wanted to endorse a moral theory that committed to the statement that humans have the same moral status of animals. Mill solves this problem in his treatise by establishing higher and lower kinds of pleasure.
These days, while certainly no consensus exists, there are more philosophers who endorse the moral status of animals. Mill, while aware that considerations of all sentient beings factor into moral decisions, probably would not grant animals the degree of morality or sentience that science and philosophy would feel comfortable granting them today. In this light, Mill's differentiation of kinds of pleasure seems tenuous.
To Mill's credit, he suggests in the next part of this chapter that this separation of kinds of pleasure is not necessary to his account of morality, because utilitarian calculations would naturally espouse a noble moral character effecting the same ends as the model of higher pleasures would. Of course, Mill probably would not have granted animals the potential for noble character, which would bring us back to the same critique. Animals also interface with our society in a way different from humans, so the dependency of utilitarian theory on societal harmony could pose a problem to animal inclusivity.
This is not to say that utilitarianism is incompatible with an assertion of the moral status of animals. Quite the contrary, the utilitarian principles of acting according to the happiness of all individuals are some of the most compelling grounds for treating animals well. The point being made here is that the finer points of utilitarian theory would have to be modified from Mill's reasoning in order to accommodate animals, before the theory would be useful to this end.
It is worth noting, as an aside, the move Mill makes in stating that the relative value of pleasures is determined by the majority preference of those people who have experienced all pleasures being considered. This is a very democratic conception of the good, in contrast with theories that posit absolute values of different things, irrespective of people's feelings towards them. This abstractly reflects Mill's overarching philosophical emphasis on the role of the individual in determining the course and moral status of society.