In olden times the ones who were considered worthy to be called masters were subtle, spiritual, profound, wise. Their thoughts could not be easily understood.
Since they were hard to understand I will try to make them clear. They were cautious like men wading a river in winter. They were reluctant like men who feared their neighbors. p. 18 They were reserved like guests in the presence of their host. They were elusive like ice at the point of melting. They were like unseasoned wood. They were like a valley between high mountains. They were obscure like troubled waters. (They were cautious because they were conscious of the deeper meanings of life and its possibilities.)
We can clarify troubled waters by slowly quieting them. We can bring the unconscious to life by slowly moving them. But he who has the secret of the Tao does not desire for more. Being content, he is able to mature without desire to be newly fashioned.