Related Clues:

• Rule to live by
• The light bulb, to Edison
• "The very ___!"
• Flash of brilliance
• Creative thought
• It may be seminal
• Thesis basis
• Fanciful notion
• Brainstorming session result
• Bean concoction?
• C.I.A. director under Clinton and Bush
• "Ah-ha" predecessor
• Approximation
• Creative germ
• It may come to mind