Almost twenty-five years after his death, Richard Courant remains a highly controversial figure. The deep affection he inspired among friends, colleagues and students is still matched by distrust and dislike in much of the mathematical community. He was a man of such contradictions in character and action that one of his colleagues, resorting to an accepted mathematical method of proof, claimed "by contradiction" that he simply did not exist. But exist he did.

On April 1, 1933, he was an internationally famous and influential German professor, the director of the first institute in the world devoted entirely to mathematics, a trusted adviser of the education ministry, a successful author and editor, a man surrounded by a mathematical family of gifted students. Eight days later, he was dismissed from his position by the Nazis. Through friends, he obtained a modest position in the United States at a university with no mathematical reputation whatsoever.

What followed - the founding and development of one of America's most important centers of applied mathematics, the Courant Institute at New York University - is one of the great success stories of mathematics.