Should not be attributed to Aesop. It's straight out of one of the billions of modern-day self-help books, Return to Love: Reflections on the Principles of "A Course in Miracles" by Marianne Williamson--this in the religious sub-genre. A Course In Miracles is based on the teachings of a woman who transcribed a Voice in her head.
If you read the rest of the passage from Williamson it's clear it's fear of inadequacy that is being discussed, one's own and that of other people who might feel insecure if you shine too much. Along with other things.
"We ask ourselves, Who am I to be brilliant, gorgeous, talented, fabulous? Actually, who are you not to be? You are a child of God. Your playing small doesn't serve the world....We were born to make manifest the glory of God that is within us. It's not just in some of us; it's in everyone. And as we let our own light shine, we unconsciously give other people permission to do the same. As we are liberated from our own fear, our presence automatically liberates others."
Interesting quote, Barbara, but I don't have the same gooseflesh response that others do. When I reflect on the idea of a deepest fear, what I come up with is the scary thought that I won't be able to write all the essays and make all the music that I want to create before I die. The only antidote I've found for this fear is to be really deeply present to all my creative endeavors, to make each one of them count -- each email, each jazz solo, each warmup exercise, etc. (And, it goes without say, to be really there for my wife and children and friends, as well, and not off on Cloud 9!) In that way, I will be more likely to "die with my boots on," so to speak. (I'm fascinated by the fact that George Washington was reported to have been taking his pulse when he died.)