15.
The skilful masters (of the Dao) in old times, with a subtle and exquisite penetration, comprehended its mysteries, and were deep (also) so as to elude men's knowledge. As they were thus beyond men's knowledge, I will make an effort to describe of what sort they appeared to be.
Shrinking looked they like those who wade through a stream in winter; irresolute like those who are afraid of all around them; grave like a guest (in awe of his host); evanescent like ice that is melting away; unpretentious like wood that has not been fashioned into anything; vacant like a valley, and dull like muddy water.
Who can (make) the muddy water (clear)? Let it be still, and it will gradually become clear. Who can secure the condition of rest? Let movement go on, and the condition of rest will gradually arise.They who preserve this method of the Dao do not wish to be full (of themselves). It is through their not being full of themselves that they can afford to seem worn and not appear new and complete.
Interpretation:
This chapter is valuable because it gives direct example of what someone who practices Dao looks like. Because the daoist chooses to "go with the flow," a master daoist may look a great deal different than the fearless leader or champion of industry that we are used to thinking of as masters.
The skillful Taoist looks for the natural lines, the seams where anything may be accomplished without effort. An excellent example of this thinking is the first line of the third stanza. "Who can (make) the muddy water (clear)? Let it be still, and it will gradually become clear." Taken literally, yes, we could build water filters and water purification plants but nature will perform this action on its own given time. The taoist would wait, if he could and work with nature to find a time when the water was drinkable. Metaphorically, the taoist does not seek to overcome but to come into accord with. Therefor, he often chooses not to act, waiting rather for the ideal time.
Using this image, we begin to see why the taoist master looks so hesitating and un-masterlike. He is the master at the art of acting without acting, seeking balance, finding peace. Therefor he never attacks, never goes forth with strength. He has great strength, but it is the strength of water finding the lowest place, the flexibility of the young tree to bend in the wind, the wisdom to retire when his goal is accomplished.