Utilitarianism is an 1861 essay written by English philosopher and economist John Stuart Mill, considered to be a classic exposition and defence of utilitarianism in ethics. It was originally published as a series of three separate articles in Fraser's Magazine in 1861 before it was collected and reprinted as a single work in 1863. The essay explains utilitarianism to its readers and addresses the numerous criticism against the theory during Mill's lifetime. It was heavily criticized upon publication; however, since then, Utilitarianism gained significant popularity and has been considered "the most influential philosophical articulation of a liberal humanistic morality that was produced in the nineteenth century." Source: Wikipedia (en)