Professor Held observed his diminished classroom. So many empty desks. How was it that so many people were now unacceptable to the Nazis? He thought of some of the students who were now gone, good students, quiet, pensive souls who had only wanted to learn. What was so threatening to the Third Reich about someone wanting to understand the fundamentals of calculus? What terrible threat could a young person educated in adding and subtracting be to the world?