Noticed the other day in Berlin in Lights: The Diaries of Count Harry Kessler, 1918-1937:
I spent the evening with Pellegrini, the painter, Dürr, the writer, and Oeri, the editor of the Basler Nachrichten. Dürr advanced, clearly and fascinatingly, the theory that Conrad Ferdinand Meyer, Jacob Burkhardt, Gottfried Keller, Jeremias Gotthelf, Nietzche, Gobineau, and all the rest of the great intellectuals active in Switzerland around the middle of the nineteenth century (Gobineau was a legation counsellor at Berne) were pushed into aversion to democracy and conversion to an aristocratic philosophy of life by the spectacle presented by the victory of Swiss democracy. 1831 saw the beginning in Switzerland of a cultural levelling process which lasted until about 1875 and produced to a varying degree detestation, fear, hate, and contempt among all these men. The lower middle class, which mistook its semi-education for culture, came to power and pushed the old, highly cultivated patrician families aside. Switzerland thus forestalled developments all over Europe. at the same time there arose in the cantons petty tyrants who pursued a harsh, ruthless rule on the lower-middle-class's behalf. Since then Switzerland has become conservative.
I was very interested by this exposure of where the roots of Nietzche's 'Superman' concept and his hostile attitude toward democracy lie, and secondly, to learn that they did not derive from purely idealistic notions but were the upshot of political experience and factional sympathies aroused by his Swiss environment.
(Entry of Thursday, 21 July 1927)
Dürr is not further identified, that I can see. Ian Buruma provides many illuminating notes, but not on Dürr.