Karel was born on January 9, 1890 in Malé Svatoňovice, a village in the north of the Hradec Králové region of the Czech Republic. His father was a doctor and his mother a midwife. His older sister Helena also wrote, including a biographical memoir of her brothers. There is a museum dedicated to the family’s work in their home town. Karel attended school in Hradec Králové and Brno before graduating from Prague’s Academic High School in 1909. His student days at Charles University included semesters in Paris and Berlin and culminated with the award of a Masters degree in Philosophy in 1915.