"Well, now, that's another point," said Weston. "I've been to church as well as you when I was a boy. There's more sense in parts of the Bible than you religious people know. Doesn't it say He's the God of the living, not of the dead? That's just it. Perhaps your God does exist -- but it makes no difference whether He does or not. No, of course you wouldn't see it; but one day you will. I don't think you've got the idea of the rind -- the thin outer skin which we call life -- really clear. Picture the universe as an infinite globe with this very thin crust on the outside. But remember its thickness is a thickness of time. It's about seventy years thick in the best places. We are born on the surface of it and all our lives we are sinking through it. When we've got all the way through then we are what's called Dead: we've got into the dark part inside, the real globe. If your God exists, He's not in the globe -- He's outside, like a moon. As we pass into the interior we pass out of His ken. He doesn't follow us in. You would express it by saying He's not in time -- which you think comforting! In other words He stays put: out in the light and air, outside. But we are in time. We 'move with the times.' That is, from His point of view, we move away, into what He regards as nonentity, where He never follows. That is all there is to us, all there ever was. He may be there in what you call 'Life,' or He may not. What difference does it make? We're not going to be there for long!"
"That could hardly be the whole story," said Ransom. "If the whole universe were like that, then we, being parts of it, would feel at home in such a universe. The very fact that it strikes us as monstrous --"
"Yes," interrupted Weston, "that would be all very well if it wasn't that reasoning itself is only valid as long as you stay in the rind. It has nothing to do with the real universe. Even the ordinary scientists -- like what I used to be myself -- are beginning to find that out. Haven't you seen the real meaning of all this modern stuff about the dangers of extrapolation and bent space and the indeterminacy of the atom? They don't say in so many words, of course, but what they're getting to, even before they die nowadays, is what all men get to when they're dead -- the knowledge that reality is neither rational nor consistent nor anything else. In a sense you might say it isn't there. 'Real' and 'Unreal,' 'true' and 'false' -- they're all only on the surface. They give way the moment you press them."
"If all this were true," said Ransom, "what would be the point of saying it?"
"Or of anything else?" replied Weston. "The only point in anything is that there isn't any point. Why do ghosts want to frighten? Because they are ghosts. What else is there to do?"
"I get the idea," said Ransom. "That the account a man gives of the universe, or of any other building, depends very much on where he is standing."
"But specially," said Weston, "on whether he's inside or out. All the things you like to dwell upon are outsides. A planet like our own, or like Perelandra, for instance. Or a beautiful human body. All the colours and pleasant shapes are merely where it ends, where it ceases to be. Inside, what do you get? Darkness, worms, heat, pressure, salt, suffocation, stink."
The Argument from Reason comes in Ransom's responses to Weston: first, in his claim that the universe he's describing seems alien to us (in the sense that we don't feel at home in it). Second, in his question to Weston: why, if Reason is not veracious, bother to say anything at all? And I find it interesting that Lewis allows Weston a response: why do ghosts frighten? That's what they do. But of course, he's still giving Ransom a reason. Even in denying Reason, he is unable to step outside it.
The Argument from Reason is mentioned in the third book, That Hideous Strength, as well. I've quoted this passage a couple of times on my blog already, but it's so poignant I'm going to do it again:
Frost had left the dining room a few minutes after Wither. He did not know where he was going or what he was about to do. For many years he had theoretically believed that all which appears in the mind as motive or intention is merely a by-product of what the body is doing. But for the last year or so -- since he had been initiated -- he had begun to taste as fact what he had long held as theory. Increasingly, his actions had been without motive. He did this and that, he said thus and thus, and did not know why. His mind was a mere spectator. He could not understand why that spectator should exist at all. He resented its existence, even while assuring himself that resentment also was merely a chemical phenomenon. The nearest thing to a human passion which still existed in him was a sort of cold fury against all who believe in the mind. There was no tolerating such an illusion. There were not, and must not be, such things as men. But never, until this evening, had he been quite so vividly aware that the body and its movements were the only reality, that the self which seemed to watch the body leaving the dining room and setting out for the chamber of the Head, was a nonentity. How infuriating that the body should have power thus to project a phantom self!
Thus the Frost whose existence Frost denied watched his body go into the ante-room, watched it pull up sharply at the sight of a naked and bloodied corpse. The chemical reaction called shock occurred. ...
Still not asking what he would do or why, Frost went to the garage. The whole place was silent and empty; the snow was thick on the ground by this. He came up with as many petrol tins as he could carry. He piled all the inflammables he could think of together in the Objective Room. Then he locked himself in by locking the outer door of the ante-room. Whatever it was that dictated his actions then compelled him to push the key into the speaking tube which communicated with the passage. When he had pushed it as far in as his fingers could reach, he took a pencil from his pocket and pushed with that. Presently he heard the clink of the key falling on the passage floor outside. That tiresome illusion, his consciousness, was screaming to protest; his body, even had he wished, had no power to attend to those screams. Like the clockwork figure he had chosen to be, his stiff body, now terribly cold, walked back into the Objective Room, poured out the petrol and threw a lighted match into the pile. Not till then did his controllers allow him to suspect that death itself might not after all cure the illusion of being a soul -- nay, might prove the entry into a world where that illusion raged infinite and unchecked. Escape for the soul, if not for the body, was offered him. He became able to know (and simultaneously refused the knowledge) that he had been wrong from the beginning, that souls and personal responsibility existed. He half saw: he wholly hated. The physical torture of the burning was not fiercer than his hatred of that. With one supreme effort he flung himself back into his illusion. In that attitude eternity overtook him as sunrise in old tales overtakes and turns them into unchangeable stone.
This is the hideous strength of the title: the "strength" to deny God, to prefer hell to Him, to do everything one can in life to remove one's own humanity. If, while you're doing so, you're able to remove the humanity of others too, well, that's just gravy.
