[1] He received his doctorate in 1921 and soon became known as a student of Chilean historian Alberto Edwards and Oswald Spengler, with whom he had struck up a friendship in Germany.
[1] Upon returning to Chile he served as chairman of the cultural organisation the German-Chilean League and in this role had helped to introduce Spengler's thoughts to a Chilean audience.
[1] He looked to the example of Diego Portales as a strong modernizing dictator and sought to develop Chilean economic independence through the growth of a middle class.
[1] When the Nacis attempted a coup in 1938 Keller was arrested, although a presidential decree from Pedro Aguirre Cerda saw him released and he returned to study.
[1] Keller largely stayed aloof from politics after this (he did not join the rebranded Vanguardia Popular Socialista) and his 1949 novel La Locura de Juan Bernales was seen as an attack on Jorge González von Marées, with whom he had become disillusioned.