When you do battle, even if you are winning, if you continue for a long time it will dull your forces and blunt you edge...If you keep your armies out in the field for a long time, your supplies will be insufficient. Transportation of provisions itself consumes 20 times the amount transported.
It is through the dispositions of an army that its condition may be discovered. Conceal your dispositions, and your condition will remain secret, which leads to victory,; show your dispositions, and your condition will become patent, which leads to defeat.
The army ages men sooner than the law and philosophy; it exposes them more freely to germs, which undermine and destroy, and it shelters them more completely from thought, which stimulates and preserves.
There must not be lacking in our leadership something of that spirit of the Austrian corporal who, when all had fallen into ruins around him, and when Germany seemed to have fallen into chaos, did not hesitate to march forth against the vast army of victorious nations and has already turned the tables decisively against them.
Nay, number itself in armies importeth not much, where the people is of weak courage; for, as Virgil saith, It never troubles the wolf how many the sheep be.
In warfare, first lay plans which will ensure victory, and then lead your army to battle; if you will not begin with stratagem but rely on brute strength alone, victory will no longer be assured.
Of all those in the army close to the commander none is more intimate than the secret agent; of all rewards none more liberal than those given to secret agents; of all matters none is more confidential than those relating to secret operations.