This article presents a biography of Austrian physicist, Paul Ehrenfest (1880-1933). Ehrenfest was married & had 4 children. He was an internationally respected scientist – even a friend of Albert Einstein’s. However, he had such a critical mind that he “tore down his own creative ideas before he could develop them”, which gave him a sense of inadequacy. This, along with marital problems & the plight of the Jews in Germany, led to his suicide in 1933. (VM)