Untitled is the only volume of Diane Arbus' work devoted exclusively to a single project. The photographs were taken at residences for the mentally retarded between 1969 and 1971, in the last years of Arbus' life. Although she considered making a book on the subject, the vast majority of these pictures have remained unpublished until now. These photographs achieve a lyricism and an emotional purity that sets them apart from all her other accomplishments: "Finally what I've been searching for," she wrote at the time. The product of her consistently unflinching regard for reality as she...