.
Utilitarianism was introduced by the British theologian William Paley in his Principles of Moral and Political Philosophy and by the British jurist and philosopher Jeremy Bentham in his Introduction to the Principles of Morals and Legislation (Encarta). In Paley's work, utilitarianism is fused with both individualistic interests and theological moral codes, as exemplified in his understanding of virtue calling it "doing good to mankind, in obedience to the will of God, and for the sake of everlasting happiness" (Encarta). However utility really gains its shape with Bentham as he incorporates the utilitarian theory as a cornerstone for legal and political reforms. He retains the need of sacrificing for the greater good so society can attain the most important thing for human beings that is happiness or the most amount of pleasure.
Bentham defined and shaped this theory of utility into the complex equation it is today. In his explanations of the theory of utilitarianism, however, Bentham lays out "four sanctions or sources of pain and pleasure", namely, the physical, the moral, the religious, and the political" (Encarta). The physical sanction, according to Bentham, is the foundation for all the other sanctions. He also was the one to formulate the weighing of pleasures and pains, discerning them in relation of their intensity, purity, duration, propinquity or remoteness, certainty, fruitfulness, and also applying pleasure and pain to the greatest number of people for his political reforms. Bentham would communicate his theory through letters especially one of his early followers named James Mill who would raise a utilitarian son that would give the theory its most important shape.
John Stuart Mill was raised and educated from a young age to be a bright scholar. Mill did just that and holds the most popular reference for utilitarianism. One of Mill's most popular writings is an exposition of three articles he wrote for Fraser's Magazine in 1861 (Mill, vii).