“The most outstanding trait in my friend’s character was, as I had experienced myself, the unparalleled consistency in everything that he said and did. There was in his nature something firm, inflexible, immovable, obstinately rigid, which manifested itself in his profound seriousness and was at the bottom of all his other characteristics. Adolf simply could not change his mind or his nature. Everything that lay in these rigid precincts of his being remained unaltered forever.”