How did John Stuart Mill define happiness in Utilitarianism?

In his seminal work Utilitarianism, John Stuart Mill defined happiness as the presence of pleasure and the absence of pain. While his framework remained rooted in this maximization of happiness, he significantly expanded upon the views of his predecessor, Jeremy Bentham, by introducing a qualitative distinction between pleasures.123

Mill argued that pleasures differ in quality, not just in intensity or duration. He categorized these into higher and lower pleasures, asserting that some are intrinsically more valuable than others. This distinction allowed Mill to maintain that it is better to be a dissatisfied human—such as Socrates—than a satisfied fool, as the fool’s preference for lower pleasures stems from a lack of experience with the higher ones. By emphasizing these qualitative differences, Mill sought to provide a more sophisticated and nuanced account of what makes human existence worthwhile, moving beyond a purely quantitative calculation of pleasure.312