St.Louis's extreme severity towards what he called the knavish oath (_vilain serment_), that is, blasphemy, an offence for which there is no definition save what is contained in the bare name of it, is, perhaps, the most striking indication of the state of men's minds, and especially of the king's, in this respect.

Every blasphemer was to receive on his mouth the imprint of a red-hot iron.

"One day the king had a burgher of Paris branded in this way; and violent murmurs were raised in the capital and came to the king's ears.

He responded by declaring that he wished a like brand might mark his lips, and that he might bear the shame of it all his life, if only the vice of blasphemy might disappear from his kingdom.

Some time afterwards, having had a work of great public utility executed, he received, on that occasion, from the landlords of Paris numerous expressions of gratitude.