For many Jews in the 19th-20th centuries, socialism and communism were seen as paths to their social and political emancipation as human beings, a way to flee from social ostracism. Examines the lives and works of ten Jews who were socialist leaders, from Marx to Trotsky. Regarding antisemitism, it was generally seen as an evil aspect of capitalism, a special case of bourgeois racism. Assimilation of the Jews was a prerequisite of the socialist revolution. Jewish socialists adopted not only the universalism of their non-Jewish revolutionary contemporaries, but also their anti-Jewish stereotypes. Jewish self-hatred was common amongst them and affected their socialist views. In their antisemitism, Marx and Lassalle surpassed some of their non-Jewish fellow socialists. The rise of political antisemitism in the 20th century, the Dreyfus Affair, brutal pogroms, and Nazism made some of the Jewish socialists (e.g. Bernstein, Lazare) revise their views and speak out against antisemitism, but did not affect others (e.g. Luxemburg, Adler).

Explores the transformation in attitudes of the Left toward the Jews, Zionism, and Israel from the beginning of European socialism in the 1840s until the present (in particular in Germany and Austria). Socialist thought from its very origins was tainted with anti-Jewish stereotypes, including identification of Jews with money and exploitation, contempt for Judaism, etc. Many Jewish socialists shared these views, or even (like Marx or Victor Adler) took part in shaping them. At the same time, modern antisemitism, both in its conservative and racist form, was evolving in Europe. The socialist parties, e.g. the German Social Democrats, had difficulties in formulating their attitudes toward antisemitism. Some socialists maintained that there was a "kernel of truth" in antisemitism; others believed that it was a by-product of the crisis of capitalism and would disappear under socialism. Anti-Zionism also has a long history on the Left, stemming from the Marxist opposition to nationalism. Focuses on the attitudes on Jews and antisemitism of socialists and communists (Jewish and non-Jewish) such as August Bebel, Franz Mehring, Bernard Lazare, Karl Kautsky, Rosa Luxemburg, Leon Trotsky, and Bruno Kreisky. The USSR turned to antisemitism after 1945; other communist parties followed suit. It was in the USSR that the myth of Zionist-Nazi collaboration was born; it was picked up by the Left worldwide. After 1955 the Left became increasingly anti-Zionist and anti-Israel. The peculiar, albeit paradoxical, development of antisemitism on the Left in recent years is related to the forging of an anti-Israel Marxist-Islamist alliance.

The Austro-Hungarian Empire was rife with ethnic tensions that undermined the possibilities for Jewish assimilation in Central Europe. The Jews were trapped between rising German nationalism and other nationalisms. Discusses various Jewish and non-Jewish attitudes toward the "Jewish problem", whereby Jews were often stereotyped (e.g. by Rosa Luxemburg) or were considered to need a solution separate from that of European majority peoples (e.g. Nathan Birnbaum and Max Nordau). Views Nietzsche as belonging more to the philosemites than the antisemites, for whom he had great scorn; however, his complexity and obscurity provided ammunition for antisemites, including the Nazis. Herzl believed that a Jewish state was needed to provide a home for Jews suffering from antisemitism. Freud's experience of antisemitism, combined with his negative view of human nature, left no room for illusions about Austrian and German acceptance of Jews. Karl Kraus exhibited elements of Jewish self-hatred when he identified the worst elements of contemporary journalism and capitalism with Jews. Karl Lueger used political antisemitism to become mayor of Vienna. He provided a model for Hitler, who imbibed antisemitic attitudes and stereotypes from the cauldron of nationalisms that was Austria-Hungary.