What did John Stuart Mill mean by saying that it is better to be Socrates dissatisfied than a fool satisfied?

In his essay Utilitarianism (1861), John Stuart Mill modified the utilitarian philosophy he inherited from Jeremy Bentham to account for differences in the quality of pleasures.12

While Bentham focused primarily on the quantitative dimensions of pleasure—its intensity and duration—Mill argued that some pleasures are intrinsically superior to others. By distinguishing between higher and lower qualities of pleasure, Mill asserted that it is "better to be Socrates dissatisfied than a fool satisfied".312

His reasoning was that a "fool" would only prefer a life of simple, lower-quality satisfaction because they lack the experience of both higher and lower pleasures. In contrast, those who have experienced both—the "Socrates" figure—are better equipped to judge which pleasures are truly more valuable, even if pursuing those higher intellectual or moral pleasures results in a state of dissatisfaction. This distinction allowed Mill to broaden the scope of what is considered worthwhile in human existence beyond mere sensual gratification.12