If a battle can not be won do not fight it.

Subtle and insubstantial, the expert leaves no trace; divinely mysterious, he is inaudible. Thus he is master of his enemy's fate.

Carefully compare the opposing army with your own, so that you may know where strength is superabundant and where it is deficient.

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.

When I have won a victory I do not repeat my tactics but respond to circumstances in an infinite variety of ways.

Know the enemy and know yourself; in a hundred battles you will never peril.

Now this foreknowledge cannot be elicited from spirits; it cannot be obtained inductively from experience, nor by any deductive calculation.