At the end of World War I the German doctor Hans Prinzhorn began collecting art of psychiatric patients which inspired modernists such Paul Klee and Salvador Dali. Adolf Hitler perceived modernism's interest as a Jewish-Bolshevik plot aimed at degrading the Aryan soul. He stripped modernist works from German galleries and exhibited them alongside 'insane' material from Prinzhorn's collection. This was the start of Hitler's onslaught against 'degenerate' humans and by 1941 he had killed 70,000 psychiatric patients. This extermination served as the prototype for the Final Solution.