Among French Jewish intellectuals who rejected Zionism in the early twentieth century was René Worms, a sociologist who used sociological theories as well as "francojudaïsme," the French-Jewish model of assimilation, to oppose it. In 1920–21, during debates organized by the Société de sociologie de Paris on the future of Palestine and Zionism, Worms used various theories to counter Jewish nationalism. Influenced by biology and race science, he began by denying the existence of a Jewish race, emphasizing the racial heterogeneity of modern Jews. His understanding of the evolution of modern religions toward universalism, influenced by Auguste Comte and Émile Durkheim, also discredited Zionism. Finally, his sociology of nationality, interwoven with Ernest Renan's conception of the nation, precluded any national claim to Judaism. This article examines the arguments Worms made and compare them to those of other speakers in debates between sociologists in Paris.