In a room on the main floor of the Museum für Moderne Kunst in Frankfurt there is a 1967–68 work by Richard Artschwager. It shows a pornographic scene, and the authorities had a sign posted that minors under the age of 18 must be accompanied by an adult in order to view this picture. Artschwager’s work—here completely misunderstood in a puritanical fashion—has always been provocative, less because of its subject matter than because of its radical questioning of materials and hence of the conventions of looking at art. In this exhibition Artschwager presented seven works from the years 1990