Jews have been at the heart of liberalism since the 18th century, and today they consitute an important element in liberal ranks. However, Wisse argues, the liberal attitude to Jewish persecution has been ambivalent, seeming to imply some Jewish responsibility for the outrages committed against them. The reason for this liberal ambivalence is nothing other than the survival of anti-Semitism - the most successful ideology of the 20th century, according to Wisse. Instead of meeting anti-Semitism with the outright rejection it deserves, many liberals, unwilling to accept that men can simply be driven by hatred, seek to find some reason for this hostility in the Jews themselves, thus partially condoning the crimes to which it gives rise. Thus, liberalism has itself become tainted with anti-Semitism, and even liberal Jews have accepted the moral equivalence between Zionism and racism. Wisse argues that liberals must re-examine their attitude towards the Jewish question and extend their own principles of tolerance to the Jews by condemning those who seek to persecute or annihilate them.