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.

Rewards for good service should not be deferred a single day.

The peak efficiency of knowledge and strategy is to make conflict unnecessary.

Attack the enemy's strategy.

The greatest victory is that which requires no battle.

The end and aim of spying in all its five varieties is knowledge of the enemy; and this knowledge can only be derived, in the first instance, from the converted spy. Hence it is essential that the converted spy be treated with the utmost liberality.

Spies cannot be usefully employed without a certain intuitive sagacity.