The madman’s explanation of a thing is always complete, and often in a purely rational sense satisfactory. Or, to speak more strictly, the insane explanation, if not conclusive, is at least unanswerable; this may be observed specially in the two or three commonest kinds of madness. If a man says (for instance) that men have a conspiracy against him, you cannot dispute it except by saying that all the men deny that they are conspirators; which is exactly what conspirators would do. His explanation covers the facts as much as yours. Or if a man says that he is the rightful King of England, it is no complete answer to say that the existing authorities call him mad; for if he were King of England that might be the wisest thing for the existing authorities to do. Or if a man says that he is Jesus Christ, it is no answer to tell him that the world denies his divinity; for the world denied Christ’s.
Nevertheless he is wrong. But if we attempt to trace his error in exact terms, we shall not find it quite so easy as we had supposed.
* * *
The man who cannot believe his senses, and the man who cannot believe anything else, are both insane, but their insanity is proved not by any error in their argument, but by the manifest mistake of their whole lives. They have both locked themselves up in two boxes, painted inside with the sun and stars; they are both unable to get out, the one into the health and happiness of heaven , the other even into the health and happiness of the earth. Their position is quite reasonable; nay, in a sense it is infinitely reasonable, just as a threepenny bit is infinitely circular. But there is such a thing as a mean infinity, a base and slavish eternity.
* * *
Then when this kindly world all round the man has been blackened out like a lie; when friends fade into ghosts, and the foundations of the world fail; then when the man, believing in nothing and in no man, is alone in his own nightmare, then the great individualistic motto shall be written over him in avenging irony. The stars will be only dots in the blackness of his own brain; his mother’s face will be only a sketch from his own insane pencil on the walls of his cell. But over his cell shall be written, with dreadful truth, “He believes in himself.”
Orthodoxy is the most unique apologetic for Christianity I’ve ever read. Chesterton writes weighty concepts with a kind of humorous levity that makes it fun and intriguing and compelling.
Recommendation: If you’re a doubter, read it. If you like apologetics, it’s a must read. If you enjoy a good use of words and images, give it a try.