Gunther Lewy, "Holocaust and the Christian Churches: The Catholic Church," in Encyclopaedia Judaica, Jerusalem: Keter Publishing House and New York: Macmillan, 1971, 8:910-914
Abstract by Jerry Darring
Pius XI was mostly concerned with Catholic non-Aryans, and he never condemned anti-Semitism as such. His successor, Pius XII, expressed sympathy for the victims of injustice, and he gave special attention to those who were being persecuted because of their nationality or descent, but he felt it his duty to remain impartial. Thus, when the 8,000 Jews of Rome were rounded up, he was willing to help them but he never spoke out publicly against the deportation. Throughout the war Pius XII was urged to speak out -- for example, by Roosevelt's personal representative, by the president of the Polish government in exile, and by the bishop of Berlin -- but he never did, and he was criticized for this both during and after the war. Such a public protest may have made a difference, but there is no way of knowing. A forceful stand by the pope might have resulted in a large-scale desertion from the church, especially in Germany, and it might have been perceived as aiding the cause of communism. There were papal nuncios, on the other hand, who reacted differently, especially those in Slovakia, Hungary, Rumania and Turkey.
Centuries of Christian hostility to Jews and their religion had provided the climate for the Nazi assault on Jewry, but there were other factors at work in the emergence of modern anti-Semitism. Church leaders in Germany tried to accommodate themselves to Nazi ideology, and they did so by speaking about racial purity, separating Jesus from the Jews of his time, and criticizing the "Jewish mentality." The church even cooperated in some ways, such as by supplying data from church records. But the bishops never spoke out against the murder of Jews, even though their protest against the euthanasia program had produced some results. In Germany, and also in Poland, whatever Christian aid there was for Jews, it came from individuals. In Western Europe, on the other hand, there were public declarations of solidarity with Jews by church leaders, and there were many Christian rescuers of Jews among the monastic clergy, priests and laity.