John von Neumann (1903-1957) was a Hungarian turned American mathematician. He made mathematical contributions in many areas including functional analysis, quantum mechanics, computer science, statistics, economics, game theory, geometry and hydrodynamics. He is considered one of the best mathematicians of the twentieth century.
Neumann was a member of the Manhattan Project that exploded the first atomic bomb. He provided mathematical analysis of whatever was needed. He provided operator theory of quantum mechanics.
Neumann was an outstanding mathematician and that is just about all that can be said for him. As a human being he had very little to recommend him for others admiration.
John Von Neumann. Various techniques used in connection with random digits. (1951)