Richard S. Westfall  is best known for his biography of a mathematician who was a key figure in what?
Richard S. Westfall Richard S. Westfall (April 22, 1924 – August 21, 1996) was an American academic, biographer and historian of science. He is best known for his biography of Isaac Newton and his work on the scientific revolution of the 17th century.
David Hilbert David Hilbert (] ; 23 January 1862 – 14 February 1943) was a German mathematician. He is recognized as one of the most influential and universal mathematicians of the 19th and early 20th centuries. Hilbert discovered and developed a broad range of fundamental ideas in many areas, including invariant theory and the axiomatization of geometry. He also formulated the theory of Hilbert spaces, one of the foundations of functional analysis.