 You don't believe the evidence of your senses? Of your own eyes? The giant was real enough, I grant you, Uncle, but I don't believe he was a man like us. Not Homo sapiens. It stands to reason that no generation of men such as we are can inhabit this subterranean world. Why not? Why not, please? Because if they did, they would all know about us who live on the surface. They would have communicated with us. Possibly. But that was a man-like creature, but it wasn't a man. A gigantic monkey of some sort. Hmm.