This publication brings together four texts which analyze Gerhard Richter's monumental project Atlas, an assemblage of photographs that he has collected since 1962. Atlas, which at present comprises more than 5,000 images -- ranging from political portraits to landscapes and from found photojournalistic pictures to photographs taken by the artist himself -- constitutes an ordered collection of personal visual memories from which Richter draws the themes and motifs for his ongoing exploration of the possibilities of painting. Buchloh examines Atlas as a mnemonic device, comparing Richter's assemblage to Aby Warburg's 1927 monumental project on collective memory; Chevrier distinguishes European and American uses of photography and art and positions Richter's work in contrast to that of the Photorealists and American Pop artists; Zweite discusses Atlas as a response to the tension between semantics and semiotics in Modernism; and Rochlitz analyses the complex relationship between photography and painting in contemporary art with specific reference to Richter's works Ema and Betty.