There is no place where espionage is not possible.

For them to perceive the advantage of defeating the enemy, they must also have their rewards.

The opportunity of defeating the enemy is provided by the enemy himself.

The general who wins a battle makes many calculations in his temple ere the battle is fought. The general who loses a battle makes but few calculations beforehand. Thus do many calculations lead to victory, and few calculations to defeat: how much more no calculation at all! It is by attention to this point that I can foresee who is likely to win or lose.

To capture an enemies army is better than to destroy it.

If the mind is willing, the flesh could go on and on without many things.

So there are five ways of knowing who will win. Those who know when to fight and when not to fight are victorious. Those who discern when to use many or few troops are victorious. Those whose upper and lower ranks have the same desire are victorious.