Scholarly investigation of the works of Hieronymus Bosch began with Carl justi, who in 1889 recognised the importance of the painter and those of his pictures in Spanish possession for the history of art. The first full-scale — though not entirely successful — attempt to explore the conception of the world which Bosch's works impress upon the spectator was made by Hermann Dollmayr in an essay published in 1898. During the following decades scholars concetrated first on tracing, then on examining all matterial relevant to the paintingts and drawings. Not until 1937 however, did the first monograph on Hieronymus Bosch to be written with rigouousscholarship appear. Even to-day — without any resevations whatsoever — it remains the for having stressed the master's great creative power and for having focussed attention once again, after forty years of neglect, on the problem of interpreting his œuvre.
During the last fifteen years the literature on the artist has grown enormously. For the most part it has been preoccupied with throwing light on the meaning of, unexplained details, and by so doing it has brought us nearer to understanding many doubtful points. Lotte Brand Philip's demonstration that Antichrist appears on the central panel of the Prado Adoration of the Magi has proved really fruitful for our knowledge of the master's way of looking at the world and with it the significance of his mature works depicting the life of Christ and penitent saints.
Günther Heinz, who is responsible for revising the notes and supplementing the bibliography, has examined all the paintings preserved in European collections with regard to attribution, originality and condition. His labours have been of most welcome assistance to me. I would also like to express here my sincere gratitude to all the other people who have helped me.