"In the early middle ages as in the later," writes R. I. Moore, Professor of Medieval History at the University of Newcastle-upon-Tyne, "persecution began as a weapon in the competition for political influence, and was turned by the victors into an instrument for consolidating their power over society at large." Victims like heretics and Jews, he argues, "owed their persecution in the first place not to the hatred of the people but to the decision of princes or prelates." Accusations of witchcraft, for instance, first appear in the royal and ecclesiastical courts during political intrigues. Ambitious nobles and clerics charged their rivals as Satan worshippers. When confession under torture or trial by ordeal confirmed these charges, authorities executed the guilty and often transferred the titles, powers, and estates of the guilty to their accusers. In later centuries, authorities applied the legal precedents and institutions that developed from these proceedings against increasingly independent townsmen and restive peasants.
Moore makes important contributions to understanding medieval history and the rise of the national state in Europe. Violent power wielded against a "dangerous" few is legitimized and institutionalized, ready for later use against the many. Although Moore doesn't apply his historical thesis to later history or current times, his book should be of interest to political scientists, legal scholars, criminologists, sociologists, and historians, especially those studying the tragedies of the past century--or speculating on future events.
A caveat: I'm no expert on medieval history, but I am uncomfortable with the author's de-emphasis of the role of popular prejudice in these persecutions, particularly of European Jews. Contemporary history and social research indicate that popular hatred and inter-group rivalry facilitate official persecutions of minority and outcast groups. Spontaneous persecutions by the masses occur and have occurred without official sanction or support.