Hitler Speech to the Doctors’ Union on racial purification of the German people

"The greatest achievements in intellectual life can never be produced by those of alien race but only by those who are inspired by the Aryan or German spirit. In view of the narrowness of the space within which German intellectual work and German intellectual workers have to live they had a natural moral claim to precedence and preference. If the number of foreigners admitted to take part in German intellectual life was out of proportion to the number of native Germans sharing in that life foreigners might interpret this as a recognition of the intellectual superiority of other races."