the laws of truth."

Valentin behind his tree was tearing his fingernails with
silent fury. He seemed almost to hear the sniggers of the English
detectives whom he had brought so far on a fantastic guess only to
listen to the metaphysical gossip of two mild old parsons. In his
impatience he lost the equally elaborate answer of the tall cleric,
and when he listened again it was again Father Brown who was
speaking:

"Reason and justice grip the remotest and the loneliest star.
Look at those stars. Don't they look as if they were single
diamonds and sapphires? Well, you can imagine any mad botany or
geology you please. Think of forests of adamant with leaves of
brilliants. Think the moon is a blue moon, a single elephantine
sapphire. But don't fancy that all that frantic astronomy would
make the smallest difference to the reason and justice of conduct.
On plains of opal, under cliffs cut out of pearl, you would still
find a notice-board, `Thou shalt not steal.'"

Valentin was just in the act of rising from his rigid and
crouching attitude and creeping away as softly as might be, felled
by the one great folly of his life. But something in the very
silence of the tall priest made him stop until the latter spoke.
When at last he did speak, he said simply, his head bowed and his
hands on his knees:

"Well, I think that other worlds may perhaps rise higher than
our reason. The mystery of heaven is unfathomable, and I for one
can only bow my head."