Mainly because of the strong clerical support of antisemitism, the French socialist movement finally decided to take a stand against antisemitic propaganda in the Dreyfus Affair. Until then, however, nineteenth-century French leftist movements had been outspoken in their antipathy to the Jews. They simply followed the tradition of eighteenth-century enlightenment which was the source of French liberalism and radicalism, and they considered anti-Jewish attitudes an integral part of anticlericalism.
