Intellect distinguishes between the possible and the impossible; reason distinguishes between the sensible and the senseless. Even the possible can be senseless.

Richard Courant a mathematician and Privatdozent called these people the "in group. Shortly after World War II a number of scientists suggested that Born update and translate his work into English. Despite never practising his religion Born refused to convert and his wedding on 2 August 1913 was a garden ceremony.

He retired to Bad Pyrmont in West Germany. He died in hospital in Göttingen on 5 January 1970.