 In 1910 he married Gertrud Mayer (1879–1974), who came from a pious German-Jewish merchant family. At the time, she was working as an assistant in the sanatorium of the neurologist and psychiatrist Oskar Kohnstamms (1871–1917) and was the sister of his close friends Gustav Mayer and the philosopher Ernest Mayer. Only thanks to her marriage to the already known philosopher Karl Jaspers was Gertrud Mayer able to stay in Germany during the Nazi period.