In the opening of the essay, Mill uses a metaphor that imagines disagreements between philosophers as a battle or war:
From the dawn of philosophy, the question concerning the summum bonum, or, what is the same thing, concerning the foundation of morality, has been accounted the main problem in speculative thought, has occupied the most gifted intellects and divided them into sects and schools carrying on a vigorous warfare against one another. And after more than two thousand years the same discussions continue, philosophers are still ranged under the same contending banners, and neither thinkers nor mankind at large seem nearer to being unanimous on the subject.
Mill writes that philosophers have argued about the “summum bonum”—Latin for "the highest good"—since the very origins of philosophy itself without making much progress. He imagines these philosophers as splitting themselves into enemy camps and “carrying on a vigorous warfare against one another.” Even after two thousand years, he claims, these armies continue to do battle “under the same contending battles,” without any real hope of reaching a resolution. In metaphorically describing these schools of philosophy as warring troops, Mill both highlights the futility of these debates and the necessity of moving beyond them. Mill poses utilitarianism as a mode of philosophy that, by examining the original principles of morality rather than getting distracted with specific or concrete examples, might help philosophy overcome this millennia-old fight.
In “Utilitarianism,” Mill addresses the critics of utilitarian philosophy who characterize it as a pleasure-seeking, hedonistic school of thought. He argues that while proponents of utilitarianism believe that society should be organized to maximize pleasure for the greatest number of people, they do not imagine pleasure as being limited to mere physical enjoyment, which he characterizes as a “low” form of pleasure. In explaining why he believes some people seek out such “low” pleasures instead of higher or more noble forms of pleasure, he uses a metaphor that imagines the “capacity for other nobler feelings” as a plant:
Capacity for other nobler feelings is in most natures a very tender plant, easily killed, not only by hostile influences, but by mere want of sustenance; and in the majority of young persons it speedily dies away if the occupations to which their position in life has devoted them, and the society into which it has thrown them, are not favorable to keeping that higher capacity in exercise. Men lose their high aspirations as they lose their intellectual tastes, because they have not time or opportunity for indulging them [...]
The ability of an individual to discern “high” from “low” pleasures, Mill writes, is “a very tender plant, easily killed.” His metaphor here suggests that, though most or all individuals might be born with this ability, the circumstances or conditions of their life might diminish it. He continues to develop the metaphor, arguing that this plant is vulnerable not only to external enemies but also because of a “mere want of sustenance.” In other words, if the ability to appreciate “high” pleasures is not sustained through regular or habitual access to those pleasures, then it will slowly fade. Mill’s metaphorical plant “speedily dies away” when negative social and professional factors prevent young people from developing their “high aspirations” and “intellectual tastes.” Ultimately, Mill argues that greater access to educational and intellectual resources would help the public appreciate what he considers to be the superior pleasures of the mind.
