An Introduction to the Principles of Morals and Legislation by Jeremy Bentham.
Bentham was the first major philosopher to develop and defend a utilitarian theory.
An Introduction to the Principles of Morals and Legislation is a book by the English philosopher and legal theorist Jeremy Bentham "originally printed in 1780, and first published in 1789." Bentham\'s "most important theoretical work," it is where Bentham develops his theory of utilitarianism and is the first major book on the topic.
An Introduction to the Principles of Morals and Legislation by Jeremy Bentham