Il ne faut point donner d'esprit a' ses personnages; mais savoir les placer dans des circonstances qui leur en donnent. You should not give wit to your characters, but know instead how to put them in situations which will make them witty.
I'm obviously attuned to pick up mathematics whenever I can see it. But in Mozart there is a lot of conscious use of mathematical symbolism and numbers in order to try and give messages.