For one thing, as a casual reader I'd have interpreted the two English texts in partly opposite ways. Le Guin could be saying just that there are still people doing their duty within disordered institutions, whereas Legge seems to suggest that when institutions become disordered, it will inspire some individuals to step up to the plate and act well (to try to counter the decline?).

FWIW, I have only the Gia-Fu Feng and Jane English translation, which says:

When the great Tao is forgotten,
Kindness and morality arise.
When wisdom and intelligence are born,
The great pretense begins.
When there is no peace within the family,
Filial piety and devotion arise.
When the country is confused and in chaos,
Loyal ministers appear.

So, more like the Legge. Now, I find it confusing that the decline in observation of the Taoist way is explicitly connected with an increase in benevolence and righteousness - surely those are good things? But perhaps the paradoxical message is that if everyone lived according to Tao, people wouldn't have to make efforts to be good sons or good ministers - "dutiful" behaviors would just flow from them automatically and wouldn't need to be remarked upon any more than the river's flowing downhill - so that when people move farther from the Tao, devotion and loyalty become more noticeable and identifiable as they are less ubiquitous. (Contrarily, the suggestion that more wisdom and intelligence leads to more hypocrisy, a bad thing, makes sense. The simply brutish are not necessarily hypocritical, but intellect and education give you lots of ways to rationalize hypocrisy.) Does that make sense to you?

How, incidentally, do you associate the hexagrams of the I Ching with chapters of the Tao Te Ching? Is there a list somewhere? Thanks very much!