Royal Swedish Academy of Letters, History and Antiquities
He became a member of the Swedish Academy in 1966, was permanent secretary of the Academy from 1977 to 1986, served on the Swedish Academy's Nobel Prize committee from 1968 to 1987, became a member of the Nobel Foundation in 1979 (serving as chairman from 1987 to 1993), and was an honorary member of the Royal Swedish Academy of Letters, History and Antiquities.