Anniversaries were the cause: the harbor of Hamburg is 800 years old, and Kurt A. Körber, the sponsor of the Deichtorhallen, is 80 years old. Einleuchten (Illumination), Harald Szeemann’s three-generations show, was also an anniversary for him as a curator. Twenty years ago, in Bern, he was a Dr. Livingstone, who explored the precarious terrain of a processual “social anti-form,” as he called it, in the exhibition “When Attitude Becomes Form.” In Hamburg, with 57 artists, including 14 from his erstwhile Bern team, he celebrated Einleuchten as a missa solemnis. At Documenta 5, 1972, in Kassel,