Justifying a fault doubles it.
More French Proverbs:
You cannot make a beautiful plumage out of a pig's tail.French
He that rewards flattery, begs it.
French
Fine and fine make but a slender doublet.
French
One grows used to love and to fire.
French
Horses run after benefices and asses get them.
French
What the eye doesn't see, the heart doesn't grieve over.
French