st and bring it into danger:--this
may be termed the business of the general.

41. The different measures suited to the nine
varieties of ground; the expediency of aggressive or
defensive tactics; and the fundamental laws of human nature:
these are things that must most certainly be studied.

42. When invading hostile territory, the general
principle is, that penetrating deeply brings cohesion;
penetrating but a short way means dispersion.

43. When you leave your own country behind, and take
your army across neighborhood territory, you find yourself
on critical ground. When there are means of communication
on all four sides, the ground is one of intersecting highways.

44. When you penetrate deeply into a country, it is
serious ground. When you penetrate but a little way,
it is facile ground.

45. When you have the enemy's strongholds on your rear,
and narrow passes in front, it is hemmed-in ground.
When there is no place of refuge at all, it is desperate ground.

46. Therefore, on dispersive ground, I would inspire
my men with unity of purpose. On facile ground, I would
see that there is close connection between all parts
of my army.

47. On contentious ground, I would hurry up my rear.

48. On open ground, I would keep a vigilant eye
on my defenses. On ground of intersecting highways,
I would consolidate my alliances.

49. On serious ground, I would try to ensure
a continuous stream of supplies. On difficult ground,
I would keep pushing on along the road.

50. On hemmed-in ground, I would block any way
of retreat. On desperate ground, I would proclaim
to my soldiers the hopelessness of saving their lives.

51. For it is the soldier's disposition to offer
an obstinate resistance when surrounded, to fight hard
when he cannot help himself, and to obey promptly when he
has fallen into danger.

52. We cannot enter into alliance with neighboring
princes until we are acquainted with their designs. We are
not fit to lead an army on the march unless we are familiar
with the face of the country--its mountains and forests,
its pitfalls and precipices, its marshes and swamps.
We shall be unable to turn natural advantages to account
unless we make use of local guides.

53. To be ignored of any one of the following four
or five principles does not befit a warlike prince.