An archer competing for a clay vessel shoots effortlessly, his or her skill and concentration unimpeded. If the prize is changed to a brass ornament, the hands begin to shake. If it is changed to gold, he or she squints as if going blind. The abilities do not deteriorate, but belief in them does, as he or she allows the supposed value of an external reward to cloud the vision.
ZhuangziWater becomes clear and transparent when in a quiescent stage. How much the more wonderful will be the mind of a sage when poised in quiescence! It is the mirror of heaven and earth, reflecting the ten thousand things.
Zhuangzi