Due to this experience with antisemitism, Lazare became engaged in the struggle for the emancipation of Jews, and was triumphally received at the First Zionist Congress. He travelled with Zionist leader Theodor Herzl, the two men sharing a great respect for each other, but he fell out with Herzl after a disagreement over the project whose "tendencies, processes and actions" he disapproved. In 1899 he wrote to Herzl – and by extension to the Zionist Action Committee, "You are bourgeois in thoughts, bourgeois in your feelings, bourgeois in your ideas, bourgeois in your conception of society." Lazare's Zionism was not nationalist, nor advocated the creation of a state, but was rather an ideal of emancipation and of collective organization of the Jewish proletarians.