Few natural scientists hold such a prominent place in the public imagination as Albert Einstein (1879–1955). His unique combination of scientific excellence and a truly colorful persona makes him almost mythical. Arguably, it is easy to forget the crucial role he played as a politically engaged public intellectual, grappling with the concrete issues of his day. This relatively brief, yet thorough book about Einstein’s pacifism excellently describes and explains that role. It carefully traces Einstein’s political and philosophical development, focusing on and analyzing his consistent, yet constantly developing pacifism. In addition to recounting the reasons for and substance of Einstein’s opposition to war, it also gives us an orderly overview of the development of pacifist thought in its various forms, using not least the classifications and ideas of the great Italian philosopher and historian Norberto Bobbio (1909–2004) as a pivotal point of departure. Hence, the book also serves as a useful introduction to pacifism. The fact that Einstein’s life and political activity intersected with some of the most momentous events of human history, including two world wars, makes the volume all the more lively and filled with drama. Anta has made sure to include Einstein’s own words by reproducing a number of seminal letters, articles, and speeches from Einstein’s hand. The extreme complexity of many of the issues confronted therein, not least the question of resistance to Adolf Hitler, alerts the reader to the many moral challenges and quandaries of pacifism. Above all, this book reminds us of the erudition, tenacity, moral imagination, idealism, and prudence of one of the greatest natural scientists who ever lived. The book deserves a wide readership among peace and conflict researchers.