What is the Russian's opinion of Kurtz?

The Russian remembers the first night he spoke to Kurtz: he forgot to sleep, he was so captivated. Kurtz made him "see things." He has nursed this great man through illnesses and has accompanied him on explorations to villages. Kurtz has raided the country by securing the cooperation of the nearby tribe, whose members all adore him. He loses himself in ivory hunts for weeks at a time. The Russian disagrees that Kurtz is mad.