Wake Forest University
Patrick Edwin Moran
Traditional:
水火清，金木濁，土又濁。
可學。
Simplified
水火清，金木浊，土又浊。
可学。
big5:
MABAgSBC
iǡC
GB:
ˮ壬ľǣǡ
ѧ
Translation:
Water and Fire are pure, Metal and Wood are turbid, and Earth (soil) is especially turbid.
Ke-xue
Commentary:
Fire and Water are at the top of the diagram of the Five Components of Activity that forms part of the Tai-ji Diagram. Possibly that detail has some connection with the judgment that they are the pure ones. When the Four Images (si xiang, |) are coordinated with the Five Components of Activity, there is an obvious problem -- where to put the fifth. In the Tai-ji Diagram it is placed in the center. When the Five Components of Activity are mapped onto the seasons of the year, a fifth "season" has to be created, also in the middle. It may be that Fire and Water are judged to be "pure" because they were believed to be "built on top of" the Yang part of the Yin-Yang cycle.
If Earth (soil) is mapped to the center of the Yin-Yang cycle, then it would involve greater contrasts than the others, and perhaps that would be a reason for asserting that it is especially turbid.
I think that this passage would not be particularly important to understanding Zhu Xi's philosophy except that he used the contrast between the pure and the turbid to explain why some people are easily socialized and why other people seem driven to get themselves into trouble.
-- PEM