mencius said, 'suppose the case of the whole kingdom turning in great delight to an individual to submit to him. to regard the whole kingdom thus turning to him in great delight but as a bundle of grass - only shun was capable of this. he considered that if one could not get the hearts of his parents he could not be considered a man, and that if he could not get to an entire accord with his parents, he could not be considered a son. by shun's completely fulfilling everything by which a parent could be served, gu sou was brought to find delight in what was good. when gu sou was brought to find that delight, the whole kingdom was transformed. when gu sou was brought to find that delight, all fathers and sons in the kingdom were established in their respective duties. this is called great filial piety.'