Arendt is best known for two major works that had a large impact: The first one is the book "The Origins of Totalitarianism" (published in 1951), which was a study of the Nazi and Stalin regimes. The second major work, "The Human Condition" (published in 1958), was a philosophical book on the human nature and human activities throughout Western history. Over the years, she published several influential essays on topics such as revolution, freedom, authority, tradition and the modern age.