John Stuart Mill, an admirer and follower of Bentham’s, extended and altered the theories of Jeremy Bentham in his 1861 book, Utilitarianism.
While Mill agreed with and enhanced much of Bentham’s theory, he disagreed with the belief that quantity of pleasure is better than quality. Mill noted that, with Bentham’s disregard for qualitative differences, there was no difference between the value of a human’s pleasure and the value of an animal’s pleasure. Thus, the moral status of humans is the same as the moral status of animals.
While Mill believed that pleasures differed in quality, he proved that quality could not be quantified (thus showing that Bentham’s felicific calculus was unreasonable). To Mill, only those people who had experienced high pleasures and low pleasures would be able to judge their quality, and this process would lead to the creation of a moral worth that would promote higher pleasures (which he believed were mostly intellectual), even if the lower pleasures (which he believed were mostly bodily) were momentarily more intense.
According to Mill, happiness is difficult to attain. Thus, instead of seeking pleasure, people are morally justified to instead seek out a way to reduce their total amount of pain with their actions. Mill’s form of utilitarianism also allowed for the ability to sacrifice pleasure and experience pain if the result is for the greater good of everyone.
Mill responds to critics who claim that utilitarianism asks too much of people by explaining that most good actions are not intended for the world’s benefit, but for the benefit of individuals who make up the world. This private utility is what most people attend to, and it is rare that any person has the power to be a public benefactor.