Ransom doesn't concede the Un-man is right. Rather, he concedes that the Un-man has unlimited intellectual stamina, so in any debate with a human, the human eve

Ransom doesn't concede the Un-man is right. Rather, he concedes that the Un-man has unlimited intellectual stamina, so in any debate with a human, the human eventually succumbs to his persuasion because humans reason imperfectly.