Towards the end of That Hideous Strength, as Lewis has Ransom meet with Merlin to outline how the heavenly reality is about to descend into the framework of the modern world, the male half of Lewis’s protagonist, Mark Studdock, is imprisoned in a cell within the enemy’s stronghold at Belbury.
For most of the novel thus far, the audience has been in an external position in relation to Mark and has experienced a dramatic irony in seeing him fall further and further into what has clearly been a trap all along. Now, however, we have been brought into a closer intimacy with him and all such irony is gone: he realises that his life, and possibly his soul, is in peril, and he henceforth ‘plays a role’ for the benefit of his captors. Lewis uses these chapters as a means of explaining what so revulsed him about ‘modernism’ by having Frost give voice to its most obnoxious extremes. Mark, in order to gain time, asks Frost what is to replace morality - on what ground henceforward were actions to be justified or condemned?
"If one insists on putting the question in those terms," said Frost, "I think Waddington has given the best answer. Existence is its own justification. The tendency to developmental change which we call Evolution is justified by the fact that it is a general characteristic of biological entities. The present establishment of contact between the highest biological entities and the Macrobes is justified by the fact that it is occurring, and it ought to be increased because an increase is taking place."
The notions of ‘Good’ and ‘Bad’ to Frost are illusions. Lewis uses a mixture of fictional philosophers (‘Waddington’) and real people (Huxley and his Romanes lecture at Oxford) to present the contemporary view that emotion and ‘that preposterous idea of an external standard of value which the emotion produced’ should be abolished. Motives are to be seen not as the causes of action but as its by-products. Mark recognises Frost’s arguments as the logical conclusion of thoughts which had always been part of his own view of life, but which he now rejects.
Frost then compels Mark to undergo a series of tests, the purpose of which is to eliminate from his mind moral motivations as a ground for action. These include being kept in a room which is full of subtle symbolic and surreal ‘adjustments’ - things designed to unhinge normal sensibilities and to tip him towards a kind of insanity.
There was a portrait of a young woman who held her mouth wide open to reveal the fact that the inside of it was thickly overgrown with hair. It was very skilfully painted in the photographic manner so that you could almost feel that hair; indeed you could not avoid feeling it however hard you tried. There was a giant mantis playing a fiddle while being eaten by another mantis, and a man with corkscrews instead of arms bathing in a flat, sadly coloured sea beneath a summer sunset.
Before long, Mark notices that the majority of pictures in the room have a spiritual theme, except that the pictures are twisted in their content to present a vaguely disturbing quality. As Mark pieces this together, so does the reader. We become aware that a reverse transformation is possible: as Ransom is calling down the gods, and with them, divinity and sanity, so the forces of Belbury are summoning demonic impulses to the surface:
He understood the whole business now. Frost was not trying to make him insane; at least not in the sense Mark had hitherto given to the word "insanity." Frost had meant what he said. To sit in the room was the first step towards what Frost called objectivity--the process whereby all specifically human reactions were killed in a man so that he might become fit for the fastidious society of the Macrobes. Higher degrees in the asceticism of anti-nature would doubtless follow: the eating of abominable food, the dabbling in dirt and blood, the ritual performances of calculated obscenities. They were, in a sense, playing quite fair with him--offering him the very same initiation through which they themselves had passed and which had divided them from humanity, distending and dissipating Wither into a shapeless ruin while it condensed and sharpened Frost into the hard, bright, little needle that he now was.
However, Mark is no longer duped: as the novel has become an Epic, so he has become its protagonist. The effect of all this is the opposite to that which was intended by the enemy:
As the desert first teaches men to love water, or as absence first reveals affection, there rose up against this background of the sour and the crooked some kind of vision of the sweet and the straight. Something else--something he vaguely called the "Normal"--apparently existed. He had never thought about it before. But there it was--solid, massive, with a shape of its own, almost like something you could touch, or eat, or fall in love with. It was all mixed up with Jane and fried eggs and soap and sunlight and the rooks cawing at Cure Hardy and the thought that, somewhere outside, daylight was going on at that moment. He was not thinking in moral terms at all; or else (what is much the same thing) he was having his first deeply moral experience. He was choosing a side: the Normal.
In choosing a side, Mark aligns himself with the direction the story has taken as a whole. He is now a ‘hero’ in the Epic sense. The subtleties of the political thriller have resolved into the plain alignments of a classic tale. The core theme of the novel - the battle between Good and Evil - has been approached so closely now that the reader has only to bear witness to the spectacle of its final battle. Irony has been removed.