Mill, John Stuart. "On Liberty." On Liberty and Other Writings, edited by Stefan Collini, 1989, pp. 1-116.
Hard Times’ Thomas Gradgrind is a caricature of James Mill—John Stuart’s father—the early proponent of utilitarianism, who famously educated his son in an All Facts, All the Time system of education not unlike the Gradgrind school. Like Gradgrind’s daughter Louisa, John Stuart suffered a nervous breakdown in early adulthood, finding his way to recovery through the poetry denied him in his youth. John Stuart's version of utilitarianism would be significantly more nuanced than his father's, incorporating something like the Aristotelian Principle into a conception of qualitative hedonism.