Now this foreknowledge cannot be elicited from spirits; it cannot be obtained inductively from experience, nor by any deductive calculation.
Hence the experienced soldier, once in motion, is never bewildered; once he has broken camp, he is never at a loss.
Probe him and learn where his strength is abundant and where deficient.
In war, then, let your great object be victory, not lengthy campaigns.
If their forces are substantial, prepare for them; if their forces are strong, avoid them.
You cannot know if you will be successful or not. You can only prepare for battle and it must be done with all of your heart and with all of your consciousness. In that manner, you will have an edge.