John Stuart Mill (1806-73). Utilitarianism was published in 1861 but before that Mill published his System of Logic (1843), Principles of Political Economy (1848) and On Liberty (1839). His other works include his classic Autobiography (1873). Mill retired in 1858 and became the independent MP for Westminster from 1865 to 1868. He spent the rest of his life in France and died in Avignon.
Alan Ryan is the Warden of the New College, Oxford, and before that was Professor of Politics at Princeton University. He is the author of The Philosophy of John Stuart Mill, and J.S. Mill, and the editor of the Penguin Classics edition of Utilitarianism and Other Essays.