It was advertized that the devil was going to put his tools up for sale.  On the date of the sale, the tools were placed for public inspection; each tool being marked with its sale price.

They were a treacherous lot of implements...Hatred, Envy, Jealousy, Deceit, Lying, Pride, and so on...

Laid apart from the rest was a harmless looking tool, well worn and priced very high...

"What is the name of this tool?" asked one of the purchasers, pointing to it.

That is Discouragement", tersely replied the devil.

"Why have you priced it so high?"

"Because it is more useful to me than the others.  I can pry open and get inside a man's heart with that when I cannot get near him with my other tools.  Once I get inside, I can make him do what I choose.  It is badly worn because I use it on almost everyone, since very few people know that it belongs to me."
-Author Unknown-