Oddities do not strike odd people. This is why ordinary people have a much more exciting time; while odd people are always complaining of the dulness of life.
Imagination does not breed insanity. Exactly what does breed insanity is reason. Poets do not go mad; but chess-players do. Mathematicians go mad, and cashiers; but creative artists very seldom.
Chesterton on smooth space:
Poetry is sane because it floats easily in an infinite sea; reason seeks to cross the infinite sea, and so make it finite. The result is mental exhaustion…
Chesterton on the refrain:
If any human acts may loosely be called causeless, they are the minor acts of a healthy man; whistling as he walks; slashing the grass with a stick; kicking his heels or rubbing his hands. It is the happy man who does the useless things; the sick man is not strong enough to be idle. It is exactly such careless and causeless actions that the madman could never understand; for the madman (like the determinist) generally sees too much cause in everything.
A man cannot think himself out of mental evil; for it is actually the organ of thought that has become diseased, ungovernable, and, as it were, independent. He can only be saved by will or faith. The moment his mere reason moves, it moves in the old circular rut; he will go round and round his logical circle, just as a man in a third-class carriage on the Inner Circle will go round and round the Inner Circle unless he performs the voluntary, vigorous, and mystical act of getting out at Gower Street.
As we have taken the circle as the symbol of reason and madness, we may very well take the cross as the symbol at once of mystery and of health. Buddhism is centripetal, but Christianity is centrifugal: it breaks out.