A stone being cast by the plough against a lump of earth, hastened to
open the conversation as follows:
"Virtue, which is the opposite of vice, is best fostered by the
absence of temptation!"
The lump of earth, being taken somewhat by surprise, was not prepared
with an apophthegm, and said nothing.
Since that time it has been customary to call a stupid person a
"clod."