The first proponent of utilitarianism was Jeremy Bentham (1748–1832), who was born in London to a wealthy family. To be sure, Bentham was something of a child prodigy. He was studying Latin at the age of three, and his father sent him to Queens College, Oxford, by the age of twelve. He earned a bachelor's degree at the age of fifteen and a master's degree at the age of eighteen. He trained as a lawyer, and his father had decided that Bentham would follow him into the law; he felt quite sure that his son would one day be Lord Chancellor of England (one of the most important functionaries in the government in the United Kingdom).

But Bentham soon grew disillusioned with British law — a layered, complex legal code benefiting the few more than the many — and so decided to write about the law and spent the rest of his life criticizing the existing law and suggesting ways for its improvement. In 1780 he wrote his major work Introduction of the Principles of Morals and Legislation.

Bentham might be termed the greatest of the “philosophical radicals,” since he proposed many legal and social reforms, but also devised principles on which they should be based. So his Principles was written with such reform in mind. The philosophy expressed in this book — utilitarianism — argues that the right act or policy is that which results in “the greatest happiness for the greatest number.” He later dropped “for the greatest number” portion of his principle since “the greatest happiness” could be in conflict with “the greatest number.” (For example, you could produce ten units of happiness for two people, which is a greater sum — twenty — than producing three units in five people — fifteen.)