tao teh ching 36

That which shrinks
Must first expand.
That which fails
Must first be strong.
That which is cast down
Must first be raised.
Before receiving
There must be giving[1].

This is called perception of the nature of things.
Soft and weak overcome hard and strong.

Fish cannot leave deep waters[2],
And a country's weapons should not be displayed.

[1] Lau reads all of this more in the style of, 'If you you would have such-and-such, you must first...'
[2] And he reads this as, 'A fish must not be allowed to leave the deep', citing as his reasoning the Han fei tzu (cf. the notes to the Wang Pi commentary below) where the fish is said to symbolise the ruler and the deep his power. The weapons of the state are reward and punishment and should not be revealed in case the dispensing of them in the wrong hands turns into a source of power.

The Ma wang tui text is subtly different, here, so I give the whole thing:

If you wish to shrink it,
You must certainly stretch it.
If you wish to weaken it,
You must certainly strengthen it.
If you wish to desert it,
You must certainly work closely with it.
If you wish to snatch something from it(*),
You must certainly give it something.
This is called the Subtle Light.
The submissive and the weak conquer the strong.

Fish should not be taken out of the depths;
The state's sharp weapons should not be shown to the people.

(*) I really detest (and contest) the translation of this particular line.

Wang Pi's interpretation again, is totally different. I give it in its entirety along with his commentary and some of Lynn's notes.

If you would like to gather him in, you must resolve to let him aggrandise himself. If you would like to weaken him, you must resolve to let him grow strong. If you would like to nullify him, you must resolve to let him flourish. If you would like to take him in, you must resolve to let him have his way. Such an approach is called subtle and perspicacious.

He comments: If you would remove the dangerously bold and get rid of the rebellious, you should do so by these four methods. Take advantage of the nature of the man involved, allow him to destroy himself, and do not rely on punishment as the major means for getting rid of such harmful elements. Thus the text characterises such an approach as 'subtle and perspicacious'. Let such a fellow find satis faction in hisaggrandisement, for, if you allow him satisfaction, he will seek even great aggrandisement and will then be gathered in by the mass of common folk(*). Rather than prevent him from aggrandising himself to the point where it is satisfying and divert him from trying to aggrandise himself as such, it would be better let him keep increasing it so that he brings danger back upon himself.

(*) Lynn's note: 'Gather in' translates shê, the base text reading. Ma wang tui text A has shih (grab, gather in, harvest); text B has chien (bind, grab, gather in, harvest); Fu Yi's composite text based on old manuscripts has hsi (gather in, harvest). The translation of shê as 'contract' or 'shrink' favoured by many recent English translations because these words are the opposite of 'expand' which they use to render chêng (aggrandise), seems forced and unlikely in the light of early textual variants. It is certainly not how Wang read the text of the Lao-tze. I settled on 'gather in' instead of simply 'grab' because I think it fits well with the theme of this passage that trouble-makers should be allowed to swell, ripen or mature to the point where, like ripe fruit or grain, they can be 'gathered in' or 'harvested' by the irate common folk, or, in other words, that they should be given enough rope to hang themselves.

His text continues: Softness and pliancy conquer hardness and forcefulness. Fish must not be allowed to escape to the depths. The sharp instruments of the state may not be disclosed to the people.

And his commentary: 'Sharp instruments' are devices used to profit the state. Act only in accordance with the nature of the people and do not rely on punishment to keep them in order. It is in ensuring that these devices cannot be seen, thus allowing everyone to obtain their proper place, that they are 'the sharp instruments of the state'. Disclosing them to the people means relying on punishments. If one tries to use punishment to profit the state, it will bring loss. If fish escape into the depths, they are certainly lost. If one establishes punishments as devices to profit the state and discloses them as such to the people, this also will surely mean loss(*).

(*)Lynn's note: Just as an inept fisherman scares away fish by letting them see his tackle (his 'devices'), using punishment to keep the people in order will make them hide and avoid authority...

The Han fei tzu (late 3rd. century BCE), which differs sharply in its reading from Wang Pi says:

Strong central power is the 'deep' (depths) of the ruler of men. Ministers are the 'fish' of this power. When the fish is lost to the deep, it cannot be regained. When the ruler of men loses his power to the ministers, he will never get it back... Reward and punishment are the sharp weapons of the state. On the side of the king, they keep the ministers in check. On the side of the ministers, they overpower the king. If the king is the first to show the reward, then the ministers would diminish it by claiming it to be their own virtuous action. If the ruler is the first to shoiw punishment, the ministers would add to it by claiming it to be their own forceful action. The king show reward and the ministers make use of its power; the king shows punishment and the ministers ride on its force. Thus it is said, 'Sharp instruments of the state must not be shown to anyone'

Cheng Man-ch'ing's commentary says: (The whole first part of the text) stresses a single functional principle: Wei ming (Henricks' 'subtle light', cf. above), which means 'wonderfully minute and obscure, yet brilliant...
Chapter 78 states, 'nothing in the world is softer and more supple than water, yet, for attacking the hard and strong, nothing can match it. No matter how strong a fish may be, it cannot escape the ocean filled with soft, supple water. Stretching in order to shrink, giving so as to gain, weakness overcoming strength, all indicate unorthodox strategy. Just so, a nation must not display its most potent weapons.

This chapter refers directly back to the very first, where, as you will recall, we were advised to always rid ourselves of desires in order to observe the secrets of the Tao, but always allow ourselves to have desires in order to observe its manifestations...
It also comes very close to the Vajrayana Buddhist idea of using poisons to against themselves and ultimately as a cure for themselves... Niguma says (and I quote again!):

If you don't understand that whatever appears is meditation,
What can you achieve by applying an antidote?
Perceptions are not abandoned by discarding them
But are spontaneously freed when recognized as illusory.

'Understanding whatever appears as meditation' is precisely dwelling centred within the Tao, and is the only real 'antidote' possible.
According to Wilhelm in his translation of the I Ching, a similar idea is expressed in hexagram 33, Tun, 'Retreat', and in the Gospel of Matthew, 5:39, 'But I say unto you, that ye resist not evil'.
This, however, is only part of the point. The idea here is that, as ideas and notions arise within the mind (and arise they always will), be they positive, negative or a mixture of both, if one can simply recognise them for what they are, which is to say as manifestations of the infinte and overflowing abundance of becoming, and then just leave them be, they arise, continue on their way for a while and then dissolve again without trace. If we attach to them, judging, refusing or indulging them, they take on an apparent life of their own and set up camp, creating past, presents, futures, mirror images of themselves, sub-thoughts, after-thoughts, further extrapolations and all the hundred thousand myriad possibilities of mental juggling that are our daily fare.
Left to themselves, they dissolve light drawings on water, clouds disappearing into space.

This is the last chapter but one of the first section of this book - the part that deals specifically with the Tao as ultimate reality - and it's therefore fitting that Grandfather Lao should come back to this point and emphasise the fact that all interference in the natural flow of things can only make things worse. There is only the one 'antidote', and that is to give things the space they need and then simply let them be.
A cat shut in a room with its doors and windows closed will forever be nosing about, looking for its way out, but just open those doors and windows for it and it will soon lie down in today's favourite spot and go off to sleep, not so? Our minds are just like that.