Give up sainthood, renounce wisdom,
And it will be a hundred times better for everyone.
Give up kindness, renounce morality,
And men will rediscover filial piety and love.
Give up ingenuity, renounce profit,
And bandits and thieves will disappear.
These three are outward forms alone; they are not sufficient in themselves.
It is more important
To see the simplicity,
To realise one's true nature,
To cast off selfishness
And temper desire.
 Somewhat intriguingly, the Ma wang tui text (which, be it recalled, is the earliest example of the text known to us) has:
These three sayings,
Regarded as a text, are not yet complete.
Thus we must see to it that they have the following appended:
Manifest plainness and embrace the genuine;
Lessen self-interest and make few your desires;
Eliminate learning and have no undue concern.
This last line, too, is generally taken, but with enormous reluctance, as the first line of ch. 20. Henricks argues that it is in fact the last line of this one on the basis of the internal evidence of the rhyme closing each of these lines in the Chines (p'u - 'genuine', yü - 'desires' and yu - 'anxiety'), the fact that neither example of the Ma wang tui text ends with punctuation and that, if the text speaks of 'three sayings' needing completion, there should logically be three lines appended to it as well.
Wang Pi points out that sagehood and intelligence are words pointing to the best of human talent, benevolence and righteousness are what is best in human behaviour and cleverness and mental acuity are the best of human resources. That they are expressly repudiated here is because such 'ornaments' are inadequate as they stand... Far better, therefore, to identify with simplicity and with a minimum of craving and desire.
In the light of this, Cheng's reading of the above lines is interesting in itself. He sees it as:
I believe that these three statements show that words are inadequate.
The people should be made to adhere to these principles:
'Look to the origins and maintain purity;
Diminish self and curb desires'.
In his commentary, however, he continuous to question the wisdom of Lao-tze's 'sage' (or is it that he asks us to?)... Sure, he says, the sage who can put his wisdom to work is acting (wei), and Lao-tze wants to keep the people ignorant (cf. ch. 65): 'The ancients who were most adept in ruling did not try to enlighten the people, but... gradually made them stupid'. Chapter 38 says, 'If Tao is lost, Teh appears. If Teh is lost, humanism appears. If humanism is lost, justice appears,' and chapter 49 says, '(the Sage's) mind merges with the world. The Sage treats everyone as his children'.
However, says Cheng, if he suggests that we look to the origin and maintain purity, diminish self and curb desires, how will the people then 'benefit hundredfold'? Furthermore, he adds, if man discards humanism and justice - the basic tenets of the Tao of mankind as far as the Confucians are concerned - what real hope is there of a return to parental affection and filial piety?
Doubtless wiser than myself, he refuses to speculate on such 'superfluous' ideas, but I think there's a thing or two to say on the subject that could be worthy at least of consideration.
For a start, I don't think Grandfather Lao is saying stop practicing these things... What he's actually saying is don't be a sanctimonious bullshit artist whose 'compassion' wouldn't make the pages of pulp romance and whose morality is only for judging others, an idiot whose 'knowledge' makes the word 'parochial' sound like endless galaxies and whose only real interest is me me me.
He's not saying goodness, wisdom, kindliness, morality, ingenuity and profit are evil per se. He's asking us to step beyond our own tiny versions of same and return to unselfconscious practice and self-discipline (another word, oddly enough, for freedom). That is why the Ma wang tui text insists that 'these sayings are not complete' and that they find their completion in simplicity, authenticity, unselfishness and contentment, in not imagining oneself to be anything beyond what one is and, consequently, in unselfconsciousness.
It has nothing to do with 'the people should be like this', or 'I should set a good example to the poor, iggerant masses'. It's for YOU that you need to let go of all the useless baggage and ornamentation of 'being clever', not for some imagined 'them'.