The gown does not make the monk.
More French Proverbs:
No lock avails against a hatchet.French
One must howl with the wolves.
French
It is a double pleasure to deceive the deceiver.
French
A girl without a friend is like the spring without roses.
French
A good gaper makes two gapers.
French
A noble prince or king never has a coin to bless himself.
French