About the book (from Wikipedia):
John Stuart Mill’s book Utilitarianism is a classic exposition and defence of utilitarianism in ethics. The essay first appeared as a series of three articles published in Fraser’s Magazine in 1861; the articles were collected and reprinted as a single book in 1863. Mill’s aim in the book is to explain what utilitarianism is, to show why it is the best theory of ethics, and to defend it against a wide range of criticisms and misunderstandings. Though heavily criticized both in Mill’s lifetime and in the years since, Utilitarianism did a great deal to popularize utilitarian ethics and was “the most influential philosophical articulation of a liberal humanistic morality that was produced in the nineteenth century.”
About J. S. Mill (from Wikipedia):
John Stuart Mill, FRSE (20 May 1806 – 8 May 1873) was an English philosopher, political economist and civil servant. He was an influential contributor to social theory, political theory and political economy. He has been called “the most influential English-speaking philosopher of the nineteenth century”.Mill’s conception of liberty justified the freedom of the individual in opposition to unlimited state control. He was a proponent of utilitarianism, an ethical theory developed by Jeremy Bentham. Hoping to remedy the problems found in an inductive approach to science, such as confirmation bias, he clearly set forth the premises of falsifiability as the key component in the scientific method. Mill was also a Member of Parliament and an important figure in liberal political philosophy.