The heavenly endowed nature in man is comparable to the nature of ice in water. It is the same whether the ice freezes or melts. Water's reflection of light may be much ore little, dark or bright, but in receiving the light, it is the same in all cases. The fact that whatever issues from the Way is good may be compared to the fact that water always flows downward. Water as such is the same in all cases.
Some water flows onward to the sea without becoming dirty.
Some flows only a short distance before growing turbid. Some travels a long distance before growing turbid. Some becomes extremely turbid, some only slightly so. Although water differs in being clean or turbid, we cannot say that turbid water ceases to become water. This being the case, man must make an increasing effort at purification.