Nonetheless, his accomplishments in the history of philosophy were far more influential than his contributions as an original thinker. Zeller's conception of the history of Greek thought was influenced by the dialectical philosophy of Hegel. Some critics maintain that Zeller was not alive enough to cultural context and to the idiosyncrasies of individual thinkers. Some hold that he laid too much stress upon Hegel's notion of "concept", and relied too much on the Hegelian antithesis of subject and object, though his history of Greek philosophy was nonetheless influential and highly regarded. He received the highest recognition, not only from philosophers and learned societies all over the world, but also from the German emperor and German people. In 1894 the Emperor Wilhelm II made him a ""Wirklicher Geheimrat"" with the title of ""Excellenz"," and his bust, along with that of Helmholtz, was set up at the Brandenburg Gate near the statues erected to the Emperor and Empress Frederick.