Set the troops to their tasks without imparting your designs.

And therefore those skilled in war bring the enemy to the field of battle and are not brought there by him.

Know the enemy and know yourself.

A clever general... avoids an army when its spirit is keen, but attacks it when it is sluggish and inclined to return. This is the art of studying moods. Disciplined and calm, he awaits the appearance of disorder and hubbub among the enemy. This is the art of retaining self-possession.

So in war, the way is to avoid what is strong and to strike at what is weak. Water shapes its course according to the nature of the ground over which it flows; the soldier works out his victory in relation to the foe whom he is facing.

Thus the skilful general conducts his army just as though he were leading a single man, willy-nilly, by the hand.

If you know neither the enemy nor yourself, you will succumb in every battle