But the important matter was this, that it entirely reversed the reason for optimism. And the instant the reversal was made it felt like the abrupt ease when a bone is put back in the socket. I had often called myself an optimist, to avoid the too evident blasphemy of pessimism. But all the optimism of the age had been false and disheartening for this reason, that it had always been trying to prove that we fit in to the world. The Christian optimism is based on the fact that we do not fit in to the world. I had tried to be happy by telling myself that man is an animal, like any other which sought its meat from God. But now I really was happy, for I had learnt that man is a monstrosity. I had been right in feeling all things as odd, for I myself was at once worse and better than all things. The optimist's pleasure was prosaic, for it dwelt on the naturalness of everything; the Christian pleasure was poetic, for it dwelt on the unnaturalness of everything in the light of the supernatural. The modern philosopher had told me again and again that I was in the right place, and I had still felt depressed even in acquiescence. But I had heard that I was in the wrong place, and my soul sang for joy, like a bird in spring. The knowledge found out and illuminated forgotten chambers in the dark house of infancy. I knew now why grass had always seemed to me as queer as the green beard of a giant, and why I could feel homesick at home.
The real trouble with this world of ours is not that it is an unreasonable world, nor even that it is a reasonable one. The commonest kind of trouble is that it is nearly reasonable, but not quite. Life is not an illogicality; yet it is a trap for logicians. It looks just a little more mathematical and regular than it is; its exactitude is obvious, but its inexactitude is hidden; its wildness lies in wait. I give one coarse instance of what I mean. Suppose some mathematical creature from the moon were to reckon up the human body; he would at once see that the essential thing about it was that it was duplicate. A man is two men, he on the right exactly resembling him on the left. Having noted that there was an arm on the right and one on the left, a leg on the right and one on the left, he might go further and still find on each side the same number of fingers, the same number of toes, twin eyes, twin ears, twin nostrils, and even twin lobes of the brain. At last he would take it as a law; and then, where he found a heart on one side, would deduce that there was another heart on the other. And just then, where he most felt he was right, he would be wrong.
It is this silent swerving from accuracy by an inch that is the uncanny element in everything. It seems a sort of secret treason in the universe. An apple or an orange is round enough to get itself called round, and yet is not round after all. The earth itself is shaped like an orange in order to lure some simple astronomer into calling it a globe. A blade of grass is called after the blade of a sword, because it comes to a point; but it doesn't. Everywhere in things there is this element of the quiet and incalculable. It escapes the rationalists, but it never escapes till the last moment. From the grand curve of our earth it could easily be inferred that every inch of it was thus curved. It would seem rational that as a man has a brain on both sides, he should have a heart on both sides. Yet scientific men are still organizing expeditions to find the North Pole, because they are so fond of flat country. Scientific men are also still organising expeditions to find a man's heart; and when they try to find it, they generally get on the wrong side of him.
Now, actual insight or inspiration is best tested by whether it guesses these hidden malformations or surprises. If our mathematician from the moon saw the two arms and the two ears, he might deduce the two shoulder-blades and the two halves of the brain. But if he guessed that the man's heart was in the right place, then I should call him something more than a mathematician. Now, this is exactly the claim which I have since come to propound for Christianity. Not merely that it deduces logical truths, but that when it suddenly becomes illogical, it has found, so to speak, an illogical truth. It not only goes right about things, but it goes wrong (if one may say so) exactly where the things go wrong. Its plan suits the secret irregularities, and expects the unexpected. It is simple about the simple truth; but it is stubborn about the subtle truth. It will admit that a man has two hands, it will not admit (though all the Modernists wail to it) the obvious deduction that he has two hearts. It is my only purpose in this chapter to point this out; to show that whenever we feel there is something odd in Christian theology, we shall generally find that there is something odd in the truth.
I have alluded to an unmeaning phrase to the effect that such and such a creed cannot be believed in our age. Of course, anything can be believed in any age. But, oddly enough, there really is a sense in which a creed, if it is believed at all, can be believed more fixedly in a complex society than in a simple one. If a man finds Christianity true in Birmingham, he has actually clearer reasons for faith than if he had found it true in Mercia. For the more complicated seems the coincidence, the less it can be a coincidence. If snowflakes fell in the shape, say, of the heart of Midlothian, it might be an accident. But if snowflakes fell in the exact shape of the maze at Hampton Court, I think one might call it a miracle. It is exactly as of such a miracle that I have since come to feel of the philosophy of Christianity. The complication of our modern world proves the truth of the creed more perfectly than any of the plain problems of the ages of faith. It was in Notting Hill and Battersea that I began to see that Christianity was true. This is why the faith has that elaboration of doctrines and details which so much distresses those who admire Christianity without believing in it. When once one believes in a creed, one is proud of its complexity, as scientists are proud of the complexity of science. It shows how rich it is in discoveries. If it is right at all, it is a compliment to say that it's elaborately right. A stick might fit a hole or a stone a hollow by accident. But a key and a lock are both complex. And if a key fits a lock, you know it is the right key.
But this involved accuracy of the thing makes it very difficult to do what I now have to do, to describe this accumulation of truth. It is very hard for a man to defend anything of which he is entirely convinced. It is comparatively easy when he is only partially convinced. He is partially convinced because he has found this or that proof of the thing, and he can expound it. But a man is not really convinced of a philosophic theory when he finds that something proves it. He is only really convinced when he finds that everything proves it. And the more converging reasons he finds pointing to this conviction, the more bewildered he is if asked suddenly to sum them up. Thus, if one asked an ordinary intelligent man, on the spur of the moment, "Why do you prefer civilisation to savagery?" he would look wildly round at object after object, and would only be able to answer vaguely, "Why, there is that bookcase … and the coals in the coal-scuttle … and pianos … and policemen." The whole case for civilisation is that the case for it is complex. It has done so many things. But that very multiplicity of proof which ought to make reply overwhelming makes reply impossible.