I got this from The Amber Spyglass by Philip Pullman:
A witch was tootling around in the air one day when she encountered a group of angels. The witch knew that they were older, wiser, and more powerful than she was, and she was not too keen on that. So she commanded the angels to act as her escort to her destination; after all, that seemed like the sensible thing to do. And because the angels were in fact older, wiser, and more powerful than the witch, they obeyed. When one is older, wiser, and more powerful, that is usually the sensible thing to do.
“Complicated rules to adjust behavior are a weak substitute for simple principles.” Mary Wollstonecraft ~ A Vindication of the Rights of Women