Sunzi, IV. 2-6:

To secure ourselves against defeat lies in our own hands, but the opportunity of defeating the enemy is provided by the enemy himself.

Thus the good fighter is able to secure himself against defeat, but cannot make certain of defeating the enemy.

Hence the saying: One may KNOW how to conquer without being able to DO it

Security against defeat implies defensive tactics; ability to defeat the enemy means taking the offensive. Standing on the defensive indicates insufficient strength; attacking, a superabundance of strength.

The general who is skilled in defense hides in the most secret recesses of the earth; he who is skilled in attack flashes forth from the topmost heights of heaven. Thus on the one hand we have ability to protect ourselves; on the other, a victory that is complete.

Sunzi (more widely known as Sun Tzu) is one of the better known Chinese thinkers, probably because he has the kind of smartness that's clear and simple. He was a military general commanding troops a little more than 500 years before the birth of Christ. Actually, he started out as a landless aristocrat (always a dangerous type -- see all the trouble that second sons of noble families stirred up through Europe's history), worked as a mercenary and wrote a book of 13 chapters describing the way to win wars. On the weight of that slender volume, he landed himself a gig leading troops for the rather ratty and disorganized Kingdom of Wu, which suddenly started winning battles under his command. He vanished after his scrappy little kingdom defeated the Kingdom of Chu, the Apollo Creed of China's Spring and Autumn Period.

His little book became the basis not only for military tactics, but also the philosophical underpinning of wushu, or martial arts. Everything from kung fu to aikido to silat to Ultimate Fighting owes something to this guy.

The Art of War has been considered required reading for military personnel for over 1,000 years -- not just in China. It's one of the texts assigned to U.S. Marines and has been part of German military training since the 1800s. And, of course, was part of that whole voguey Asian thing in American corporate culture in the 1980s -- management secrets of the Far East and all that.

I like this particular passage in part because it reminds me of that St. Francis prayer about the things I can change and the things I can't change (and the wisdom to know the difference), and in part because it reminds me of Don Rumsfeld's famous (and much maligned) "unknown unknowns." Which are, as Sun Tzu tells us, the very best defense.