A plain of sad-coloured cloud lay along the level of the top of the Cathedral dome, so that the ball and the cross looked like a buoy riding on a leaden sea. As the flying ship swept towards it, this plain of cloud looked as dry and definite and rocky as any grey desert. Hence it gave to the mind and body a sharp and unearthly sensation when the ship cut and sank into the cloud as into any common mist, a thing without resistance. There was, as it were, a deadly shock in the fact that there was no shock. It was as if they had cloven into ancient cliffs like so much butter. But sensations awaited them which were much stranger than those of sinking through the solid earth. For a moment their eyes and nostrils were stopped with darkness and opaque cloud; then the darkness warmed into a kind of brown fog. And far, far below them the brown fog fell until it warmed into fire. Through the dense London atmosphere they could see below them the flaming London lights; lights which lay beneath them in squares and oblongs of fire. The fog and fire were mixed in a passionate vapour; you might say that the fog was drowning the flames; or you might say that the flames had set the fog on fire. Beside the ship and beneath it (for it swung just under the ball), the immeasurable dome itself shot out and down into the dark like a combination of voiceless cataracts. Or it was like some cyclopean sea-beast sitting above London and letting down its tentacles bewilderingly on every side, a monstrosity in that starless heaven. For the clouds that belonged to London had closed over the heads of the voyagers sealing up the entrance of the upper air. They had broken through a roof and come into a temple of twilight.

They were so near to the ball that Lucifer leaned his hand against it, holding the vessel away, as men push a boat off from a bank. Above it the cross already draped in the dark mists of the borderland was shadowy and more awful in shape and size.

Professor Lucifer slapped his hand twice upon the surface of the great orb as if he were caressing some enormous animal. “This is the fellow,” he said, “this is the one for my money.”

“May I with all respect inquire,” asked the old monk, “what on earth you are talking about?”

“Why this,” cried Lucifer, smiting the ball again, “here is the only symbol, my boy. So fat. So satisfied. Not like that scraggy individual, stretching his arms in stark weariness.” And he pointed up to the cross, his face dark with a grin. “I was telling you just now, Michael, that I can prove the best part of the rationalist case and the Christian humbug from any symbol you liked to give me, from any instance I came across. Here is an instance with a vengeance. What could possibly express your philosophy and my philosophy better than the shape of that cross and the shape of this ball? This globe is reasonable; that cross is unreasonable. It is a four-legged animal, with one leg longer than the others. The globe is inevitable. The cross is arbitrary. Above all the globe is at unity with itself; the cross is primarily and above all things at enmity with itself. The cross is the conflict of two hostile lines, of irreconcilable direction. That silent thing up there is essentially a collision, a crash, a struggle in stone. Pah! that sacred symbol of yours has actually given its name to a description of desperation and muddle. When we speak of men at once ignorant of each other and frustrated by each other, we say they are at cross-purposes. Away with the thing! The very shape of it is a contradiction in terms.”

“What you say is perfectly true,” said Michael, with serenity. “But we like contradictions in terms. Man is a contradiction in terms; he is a beast whose superiority to other beasts consists in having fallen. That cross is, as you say, an eternal collision; so am I. That is a struggle in stone. Every form of life is a struggle in flesh. The shape of the cross is irrational, just as the shape of the human animal is irrational. You say the cross is a quadruped with one limb longer than the rest. I say man is a quadruped who only uses two of his legs.”

The Professor frowned thoughtfully for an instant, and said: “Of course everything is relative, and I would not deny that the element of struggle and self-contradiction, represented by that cross, has a necessary place at a certain evolutionary stage. But surely the cross is the lower development and the sphere the higher. After all it is easy enough to see what is really wrong with Wren’s architectural arrangement.”

“And what is that, pray?” inquired Michael, meekly.

“The cross is on top of the ball,” said Professor Lucifer, simply. “That is surely wrong. The ball should be on top of the cross. The cross is a mere barbaric prop; the ball is perfection. The cross at its best is but the bitter tree of man’s history; the ball is the rounded, the ripe and final fruit. And the fruit should be at the top of the tree, not at the bottom of it.”

“Oh!” said the monk, a wrinkle coming into his forehead, “so you think that in a rationalistic scheme of symbolism the ball should be on top of the cross?”

“It sums up my whole allegory,” said the professor.

“Well, that is really very interesting,” resumed Michael slowly, “because I think in that case you would see a most singular effect, an effect that has generally been achieved by all those able and powerful systems which rationalism, or the religion of the ball, has produced to lead or teach mankind. You would see, I think, that thing happen which is always the ultimate embodiment and logical outcome of your logical scheme.”

“What are you talking about?” asked Lucifer. “What would happen?”

“I mean it would fall down,” said the monk, looking wistfully into the void.

Lucifer made an angry movement and opened his mouth to speak, but Michael, with all his air of deliberation, was proceeding before he could bring out a word.

“I once knew a man like you, Lucifer,” he said, with a maddening monotony and slowness of articulation. “He took this–”

“There is no man like me,” cried Lucifer, with a violence that shook the ship.

“As I was observing,” continued Michael, “this man also took the view that the symbol of Christianity was a symbol of savagery and all unreason. His history is rather amusing. It is also a perfect allegory of what happens to rationalists like yourself. He began, of course, by refusing to allow a crucifix in his house, or round his wife’s neck, or even in a picture. He said, as you say, that it was an arbitrary and fantastic shape, that it was a monstrosity, loved because it was paradoxical. Then he began to grow fiercer and more eccentric; he would batter the crosses by the roadside; for he lived in a Roman Catholic country. Finally in a height of frenzy he climbed the steeple of the Parish Church and tore down the cross, waving it in the air, and uttering wild soliloquies up there under the stars. Then one still summer evening as he was wending his way homewards, along a lane, the devil of his madness came upon him with a violence and transfiguration which changes the world. He was standing smoking, for a moment, in the front of an interminable line of palings, when his eyes were opened. Not a light shifted, not a leaf stirred, but he saw as if by a sudden change in the eyesight that this paling was an army of innumerable crosses linked together over hill and dale. And he whirled up his heavy stick and went at it as if at an army. Mile after mile along his homeward path he broke it down and tore it up. For he hated the cross and every paling is a wall of crosses. When he returned to his house he was a literal madman. He sat upon a chair and then started up from it for the cross-bars of the carpentry repeated the intolerable image. He flung himself upon a bed only to remember that this, too, like all workmanlike things, was constructed on the accursed plan. He broke his furniture because it was made of crosses. He burnt his house because it was made of crosses. He was found in the river.”