6.12

"Therefore, if you know the ground of battle and know the day of battle, then you can be a thousand li (away) and still join in battle."
- Sun Tzu

The foundation of success for Sun Tzu is knowledge. This is the pillar upon which everything else rests. As Sun Tzu tells us in Book 3, "[K]now the other and know the self, and in one hundred battles, there will be no danger." 

It is important to know, though, that what Sun Tzu means by "knowledge" is not how we normally think of knowledge. We tend to think of knowledge as "holding facts in our minds" - for example, knowing Abraham Lincoln is our 16th president or that two plus two equals four. We call this kind of knowledge "declarative knowledge."

What Sun Tzu means by knowing the ground and day of battle is different from this kind of knowledge. What Sun Tzu means by knowing the ground and time of battle is determining what is the most advantageous place and time for battle. Determining this is a matter of carefully analyzing the five factors mentioned in Book 1 (The Way, Heaven, Ground, General, and Methods).

Thus, the knowledge that Sun Tzu is speaking of is not simply the ability to articulate facts (i.e. what has happened), but to determine what the best course of action is and when the best time to take this course is, given one's current understanding of the situation. We can call this kind of knowledge "decisive knowledge."

For Sun Tzu, decisive knowledge gives one a sense of control (zhi), which is why he tells us that if you know the time and place of battle, "you can be a thousand li away and still join in battle." (A li is about a third of a mile, so over 300 miles away). This is because deciding, based on analysis, the place and day of battle allows you to march unhampered, take up a position that the enemy cannot attack, and attack where the enemy is unguarded (see 6.4).

In your own life, you need to develop your capacity for decisive knowledge. You need to look at your situation, analyze it, and determine when and where you are going to make your move. After knowing this, you can plan a route to effectively getting there.

It is important to note that decisive knowledge is not absolute. Your situation is constantly changing. In these situations (as we'll see in later Books), you'll need to hold your position and wait. But you always decide these decisions based analysis of the situation.