In 1880 he joined a group of German socialists in Zürich who were supported financially by Karl Höchberg
Karl Höchberg (8 September 1853 – 21 June 1885), scion of a wealthy banking family, was a German social-reformist writer, publisher and economist, with a Jewish family background, who acted under the pseudonyms Dr. Ludwig Richter and R.F. Seifert. In 1876, he became a member of the Social Democratic Workers Party of Germany (SDAP). From 1877 to 1878, he was responsible for editing the Zukunft ("Future") magazine. He was in exile in Switzerland from 1878 onwards, first to avoid conscription to the Prussian military, and then due to the anti-socialist laws. Eduard Bernstein and Karl Kautsky were his secretaries and pupils in Zurich.