When we are confronted with images of and memoirs from the Holocaust and subsequent cases of vast cruelty and suffering, is our impulse to empathize put at risk by the possibility of becoming numb to horror? Carolyn J. Dean's provocative new book addresses the ways we evade our failures of empathy in the face of massive suffering: Has exposure (or overexposure) to representations of pain damaged our ability to feel? Do the frequent claims that...