John Stuart Mill was the "Saint of Rationalism" according to William Gladstone. But in the first definitive biography of Britain's greatest public intellectual, Richard Reeves reveals Mill as a passionate man of action: a philosopher, radical MP and a reformer who profoundly shaped Victorian society and continues to illuminate our own. To understand John Stuart Mill and his contribution, Richard Reeves explores his life and work in tandem. This book is a riveting and authoritative biography of a man raised to promote happiness, whose life was spent in the pursuit of truth and liberty for all.