fled in
all directions.]

5. If you are anxious to fight, you should not go to meet
the invader near a river which he has to cross.

[For fear of preventing his crossing.]

6. Moor your craft higher up than the enemy, and facing the
sun.

[See supra, ss. 2. The repetition of these words in
connection with water is very awkward. Chang Yu has the note:
"Said either of troops marshaled on the river-bank, or of boats
anchored in the stream itself; in either case it is essential to
be higher than the enemy and facing the sun." The other
commentators are not at all explicit.]

Do not move up-stream to meet the enemy.

[Tu Mu says: "As water flows downwards, we must not pitch
our camp on the lower reaches of a river, for fear the enemy
should open the sluices and sweep us away in a flood. Chu-ko Wu-
hou has remarked that 'in river warfare we must not advance
against the stream,' which is as much as to say that our fleet
must not be anchored below that of the enemy, for then they would
be able to take advantage of the current and make short work of
us." There is also the danger, noted by other commentators, that
the enemy may throw poison on the water to be carried down to
us.]

So much for river warfare.
7. In crossing salt-marshes, your sole concern should be to
get over them quickly, without any delay.

[Because of the lack of fresh water, the poor quality of the
herbage, and last but not least, because they are low, flat, and
exposed to attack.]

8. If forced to fight in a salt-marsh, you should have
water and grass near you, and get your back to a clump of trees.

[Li Ch`uan remarks that the ground is less likely to be
treacherous where there are trees, while Tu Mu says that they
will serve to protect the rear.]

So much for operations in salt-marches.
9. In dry, level country, take up an easily accessible
position with rising ground to your right and on your rear,

[Tu Mu quotes T`ai Kung as saying: "An army should have a
stream or a marsh on its left, and a hill or tumulus on its
right."]

so that the danger may be in front, and safety lie behind. So
much for campaigning in flat country.
10. These are the four useful branches of military
knowledge

[Those, namely, concerned with (1) mountains, (2) rivers,
(3) marshes, and (4) plains. Compare Napoleon's "Military
Maxims," no. 1.]

which enabled the Yel