4.4

"Those skilled in defense conceal themselves in the nine grounds below. Those skilled in attack move to the nine heavens above. Thus, they are able to protect themselves and achieve total victory."
- Sun Tzu

Using metaphor (the nine grounds below, the nine heavens above), Sun Tzu here describes his strategy for implementing an effective attack and defense, based on his principle of deception.

For Sun Tzu, deception requires two skills: concealment, or the ability to hide one's situation and positioning from the enemy, and surprise, or the ability to attack the enemy when he least expects it and where he is unprepared.

Concealment is used for defense: if the enemy doesn't know an army's situation or positioning, he doesn't know where to attack. Surprise is used for attack: if the enemy caught unprepared, he will quickly rush to defend where he is being attack, leaving openings in other areas and giving you control over the dynamic of the battle.

Concealment and surprise, though distinct, are not separate concepts. Surprising the enemy is only possible if he does not know an army's positioning. Likewise, concealing one's army can last only if an army is able to keep the enemy distracted with wondering when and where the next attack will be. Concealment and surprise feed into each other in a powerful cycle, allowing for a simultaneous attack and defense.

Sun Tzu tells us it is by following these principles that one can achieve total victory. If you recall from earlier passages, total victory refers to a victory where the enemy is dominated and all the gains from the victory are intact. This is the most economical victory one can achieve.

The concealment-surprise strategy helps one to achieve total victory because it is not focused on the size or strength of one's force, but on the psychology of the enemy. The most economical way to defeat an opponent is not by destroying him physically, but mentally, undermining his motivation to fight.

This strategy is just as important for you as it is for an army in Sun Tzu's time. You must make a concerted effort to conceal your intentions and plans. You should always operate in cloak of darkness so that others are not aware of what you are trying to achieve.

Likewise, you should always strive to take action quickly and unexpectedly when you decide to make a move. Always take the line of least expectation.

Being concealed and striking unexpectedly will give you the momentum to overcome any resistance and achieve victory.