" Lyra looked at the two of them, so utterly different: Iofur so glossy and powerful, immense in his strength and health, splendidly armored, proud and kinglike; and Iorek smaller, though she had never thought he would look small, and poorly equipped, his armor rusty and dented. But his armor was his soul. He had made it and it fitted him. They were one. Iofur was not content with his armor; he wanted another soul as well. He was restless while Iorek was still. "

― Philip Pullman , The Golden Compass (His Dark Materials, #1)