About the Author
Professor Frank Zollner wrote his doctoral theses on artistic and architectural theory (1987) and Leonardo da Vinci (1996). He has written numerous publications on the art and artistic theory of the Renaissance and on Paul Klee. Since 1996 he has been Professor of Renaissance and Modern Art at Leipzig University. He is also the author of Taschen's 1998 monograph on Leonardo da Vinci. Johannes Nathan studied art history at New York University (B.A.) and the Courtauld Institute of Art in London (M.A.), where he earned his Ph.D. in 1995 with a dissertation on the working methods of Leonardo da Vinci. He has taught New York University and at the University of Berne, Switzerland, where he is now directing the "artcampus" project. He is the author of a range of publications on the art of the Italian Renaissance, as well as on artists' working methods.