Know how to use evasion. That is how smart people get out of difficulties. They extricate themselves from the most intricate labyrinth by some witty application of a bright remark. They get out of a serious contention by an airy nothing or by raising a smile. Most of the great leaders are well grounded in this art. When you have to refuse something, often the most courteous way is to just change the subject. And sometimes it proves the highest understanding to act like you do not understand.

THE ART OF WORLDLY WISDOM BY BALTHASAR GRACIAN
TRANSLATED BY JOSEPH JACOBS 1892