" I’ve worked with volunteers before,” he began. “It’s important not to… not to treat them like servants. We may feel that they are laboring to obtain a heavenly reward, and should therefore work harder than they would for money; but they don’t necessarily take that attitude. They feel they’re working for nothing, and doing a great kindness to us thereby; and if we seem ungrateful they will work slowly and make mistakes. It will be best to rule them with a light touch. "
― Ken Follett , The Pillars of the Earth (Kingsbridge, #1)