Can the greatness of one of the most remarkable musicians of the Western world excuse positions among the most abject? And above all: can it justify ignoring them? Their manifestations are unfortunately beyond doubt: in his writings of which we will find new translations here, as well as an unpublished one. But can we say that the librettos and even the music of his operas are anti-Semitic? Wagner's anti-Semitism is a controversial subject in the specialized literature, of which we find here a review that is both critical and polemical, bringing into play the biographical survey, the general history, the history of anti-Semitism, music history, musicology, semiology, psychoanalysis and aesthetics. And how to explain it? Why he would have been a Jew himself? Many of his contemporaries believed it, as the vast collection of caricatures by the composer brought together in this work attests. At the end of a close examination, it is necessary to ask disturbing questions: should the performance or representation of Wagner's operas be prohibited? Should Bayreuth be closed?