The canonical statement of Mill's utilitarianism can be found in Utilitarianism. This philosophy has a long tradition, although Mill's account is primarily influenced by Jeremy Bentham and Mill's father James Mill.

Jeremy Bentham's famous formulation of utilitarianism is known as the "greatest-happiness principle". It holds that one must always act so as to produce the greatest aggregate happiness among all sentient beings, within reason. Mill's major contribution to utilitarianism is his argument for the qualitative separation of pleasures. Bentham treats all forms of happiness as equal, whereas Mill argues that intellectual and moral pleasures (higher pleasures) are superior to more physical forms of pleasure (lower pleasures). Mill distinguishes between happiness and contentment, claiming that the former is of higher value than the latter, a belief wittily encapsulated in the statement that "it is better to be a human being dissatisfied than a pig satisfied; better to be Socrates dissatisfied than a fool satisfied. And if the fool, or the pig, are of a different opinion, it is because they only know their own side of the question."