The Art of War by Sun Tzu

I Laying plans contd...

21. If he is secure at all points be prepared for him. If he is in superior strength evade him.

Notes by Zephyrist:

This one is a bit cryptic. If the enemy has no points of weakness, in a sense offering no points of attack then the enemy has the advantage. You should be prepared for his attack and so your battle will be to defend. If in the attack the enemy will have superior strength then you must evade him until circumstances change in your favour.

In a more modern example consider a political debate. If your enemy debate has no weakness then he will attack yours, so be prepared to answer his attacks. If his debate is stronger than yours then it would be best to evade or avoid any debate or exchange of views. Again this evasion will need to continue until the field of battle changes in your favour.