What is efficacy? It is effectiveness in submission to what is right, most effective in abiding in faithfulness to rectitude. Only thus is it an auspicious path that is sound in the beginning and sound at the end. One aims for the submission of unruliness, the rectification of error, cultivating oneself and controlling the mind, getting rid of all seeds of vicious circles, not letting any pollution remain in the mind; being utterly empty, serene and sincere, the human mentality does not arise and the mind of Tao comes into being. After rectitude comes creativity, and while flexible one is firm, and while receptive one can be strong: Whatever one creates grows, and whatever grows bears fruit, and the fruits are all good. So the submission and receptivity of abiding in rectitude is no small matter.
—The Taoist I Ching
translated by Thomas Cleary