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.
ZhuangziThe sage has the sun and moon by his side and the universe under his arm. He blends everything into a harmonious whole. . . . He blends the disparities of ten thousand years into one complete purity. All things are blended like this and mutually involve each other.
Zhuangzi