Standards are different for all things, so the standard set by man is by no means the only 'certain' standard. If you mistake what is relative for something certain, you have strayed far from the ultimate truth.

The Tao has no place for pettiness, and nor has Virtue. Pettiness is dangerous to Virtue; pettiness is dangerous to the Tao. It is said, rectify yourself and be done.

Big? Sure. But, he can't catch mice! So for your big tree. No use? Then plant it in the wasteland - in emptiness. Walk idly around it and rest under it's shadow. No axe or saw prepares its end. No one will ever cut it down. Useless? You should worry!.

That knowledge which stops at what it does not know, is the highest knowledge.

To go outside what your charge was, and to try to solve everything yourself, is dangerous.

A petty thief is put in jail. A great brigand becomes a ruler of a Nation.

Paraphrased: When Chuang Tzu was about to die, his disciples began planning a splendid funeral. However some disciples expressed concern that given a particular arrangement, birds and kites would eat his remains. Chuang Tzu replied, "Well, above ground I shall be eaten by crows and kites, below it by ants and worms. What do you have against birds?