" These riots are often blamed on the great Dominican preacher Vicente Ferrer (c. 1350-1419), afterwards canonized. But his role was much more subtle, and more sinister from the Jew’s point of view. Indeed he helped to develop a pattern of anti-Semitism which was to reverberate thunderously in the twentieth century. It is true that his public preachings were often associated with anti-Semitic hysteria and outrages. But he did not encourage rioting; on the contrary–he deplored it. He publicly condemned the 1391 riots. He thought it wicked and un-Christian that the mob should take the law into its own hands. Instead, it was the duty of the state to act, and proceed lawfully. The riots showed clearly that the Jews posed a ‘problem’ to society to which a ‘solution’ must be found. Hence Ferrer and his clerical colleagues were responsible for a series of anti-Jewish policies approved by the Spanish-favoured antipope Benedict XIII, and for the selection as King of Aragon of Ferdinand I, who began to implement them. The war against the Jews was taken out of the hands of the mob and made the official business of church and government. "
― Paul Johnson , A History of the Jews