In 1870, after one political protest, he left his service and headed for Vienna to study philosophy, and soon to Dresden, Leipzig, Berlin and Paris, receiving his Ph.D. in philosophy in 1872.
Godine 1870. nakon jedne političke demonstracije napušta službu i odlazi na studij filozofije u Beč, a zatim u Dresden, Leipzig, Berlin i Pariz, 1872. je doktorirao filozofiju.