In the first definitive biography of Britain's greatest public intellectual, Richard Reeves reveals John Stuart Mill as a passionate man of action: a philosopher, radical MP and reformer who profoundly shaped Victorian society and continues to illuminate our own. A young activist and highly-educated Cambridge Union debater, Mill would become in time the highest-ranked English thinker of the nineteenth-century, the author of the landmark essay On Liberty and one of the most passionate reformers and advocates of his revolutionary, opinionated age. As a journalist he fired off a weekly article on Irish land reform as the people of that nation starved, as an MP he introduced the first vote on women's suffrage, fought to preserve free speech and opposed slavery, and, in his private life, pursued for two decades a love affair with another man's wife. Mill also fearlessly tackled issues such as the regulation of gambling, prostitution and alcohol, as well as parliamentary reform and domestic violence. John Stuart Mill was the 'Saint of Rationalism' according to William Gladstone. But in this biography, Richard Reeves reveals Mill as a passionate man of action, a philosopher, radical MP and reformer who profoundly shaped Victorian society and continues to illuminate our own.