It is better to be a person who claims himself to be a fool, yet speak and do things with wit. Rather than to be a man who claims to be a wit or intelligent man, and instead do and say foolish things.
It is better to be a clever clown than to design an atom bomb and have Hiroshima and Nagasaki on your conscience. That's what it means.
it means what King Frog said.. Exactly!
Take a look at the concept of the "wise fool." That might give you an idea.
It's better to be an idiot who talks well than someone who only says stupid things. It loses a lot in translation. =P