David Hilbert was a German mathematician and philosopher of mathematics and one of the most influential mathematicians of all time.
Hilbert in 1912
Hilbert in 1886
Hilbert in 1907
The Mathematical Institute in Göttingen. Its new building, constructed with funds from the Rockefeller Foundation, was opened by Hilbert and Courant in 1930.
Hermann Klaus Hugo Weyl was a German mathematician, theoretical physicist, logician and philosopher. Although much of his working life was spent in Zürich, Switzerland, and then Princeton, New Jersey,
Hermann Weyl (left) with Ernst Peschl
The Theory of Groups and Quantum Mechanics (translated from the second, revised German edition by Howard P. Robertson)