Martha Graham to Agnes de Mille...

"There is a vitality, a lifeforce, an energy, a quickening that is translated through you into action, and because there is only one of you in all of time, this expression is unique.  And if you block it, it will never exist through any other medium and it will be lost.  The world will not have it.  It is your business to keep it yours clearly and directly, to keep the channel open.  You do not even have to believe in yourself or your work.  You have to keep yourself open and aware of the urges that motivate you.  Keep the channel open... No artist is pleased (there is) no satisfaction what(so)ever at any time.  There is only a queer divine dissatisfaction, a blessed unrest that keeps us marching and makes us more alive than the others."