Answering a fool

This is why it is important to consider the validity of a question before answering:

Proverbs 26:4 (KJV) Answer not a fool according to his folly, lest thou also be like unto him.

And this is why it is important to answer:

Proverbs 26:5 (KJV) Answer a fool according to his folly, lest he be wise in his own conceit.