The deepest rivers flow with the least sound.
A cowardly cur barks more fiercely than it bites.
Nothing is strong that may not be endangered even by the weak.
Doctors cure the more serious diseases with harsh remedies. Curtius Medici graviores morbos asperis remediis curant
A timid dog barks more violently than it bites. Curtius Canis timidus vehementius latrat quam mordet
Habit is stronger than nature.