Dragons Again

J. R. R. Tolkien describes the dragon, Chrysophylax:

For though the oaths he had taken should have burdened his conscience with sorrow and a great fear of disaster, he had, alas! no conscience at all. (J. R. R. Tolkien, Farmer Giles of Ham.)

As the people of Ham discovered, it does little good to negotiate with someone who has no conscience.