Barry Bergdoll, The Philip Johnson Chief Curator of Architecture and Design, The Museum of Modern Art, and professor, Columbia University. In the fourth lecture, originally delivered at the National Gallery of Art on April 28, 2013, architectural historian Barry Bergdoll considers the role of the exhibition as an instrument for reform in the movement for better housing for the working classes, in the institution of city planning as a modern discipline, and in the emergence of the artistic avant-garde in the years around 1900, all cases of projecting alternative futures.