In the Holocaust museum in Jerusalem, Yad Vashem, 7,318 Poles are named as Righteous Among the Nations, an award given to gentiles who rescued Jews during the Holocaust. There were 32 million Catholic Poles in Poland in 1939. The arithmetic may be crude but around one in 4,000 took the risk, albeit perilous, to save a Jewish life. Of the million Jewish children in Poland in 1939, 5,000 survived. My mother was one of them, saved in part by the heroism of Pola Binkowska, a young Catholic woman who loved her. It’s an age-old question. What would you have done?...