Why did John Stuart Mill say that it is better to be Socrates dissatisfied than a fool satisfied?

John Stuart Mill used the phrase "it is better to be Socrates dissatisfied than a fool satisfied" to illustrate his departure from the purely quantitative approach to pleasure held by his predecessor, Jeremy Bentham.12

While Bentham focused on the intensity and duration of pleasures, Mill argued that there are qualitative differences between them. He maintained that some pleasures are intrinsically superior to others, regardless of their quantitative measures. According to Mill, the "fool" might claim to be satisfied with lower-quality pleasures only because they lack the experience of higher-quality pleasures. By contrast, those who have experienced both—such as the intellectual or moral pursuits associated with a figure like Socrates—would recognize the inherent value of the higher quality, even if it comes with the dissatisfaction of a more complex existence. This distinction allowed Mill to broaden the utilitarian view of what is worthwhile in human life, moving beyond a narrow focus on simple sensory gratification.312