annot be so calculated."]

6. Knowledge of the enemy's dispositions can only be
obtained from other men.

[Mei Yao-ch`en has rather an interesting note: "Knowledge
of the spirit-world is to be obtained by divination; information
in natural science may be sought by inductive reasoning; the laws
of the universe can be verified by mathematical calculation: but
the dispositions of an enemy are ascertainable through spies and
spies alone."]

7. Hence the use of spies, of whom there are five classes:
(1) Local spies; (2) inward spies; (3) converted spies; (4)
doomed spies; (5) surviving spies.
8. When these five kinds of spy are all at work, none can
discover the secret system. This is called "divine manipulation
of the threads." It is the sovereign's most precious faculty.

[Cromwell, one of the greatest and most practical of all
cavalry leaders, had officers styled 'scout masters,' whose
business it was to collect all possible information regarding the
enemy, through scouts and spies, etc., and much of his success in
war was traceable to the previous knowledge of the enemy's moves
thus gained." [1] ]

9. Having LOCAL SPIES means employing the services of the
inhabitants of a district.

[Tu Mu says: "In the enemy's country, win people over by
kind treatment, and use them as spies."]

10. Having INWARD SPIES, making use of officials of the
enemy.

[Tu Mu enumerates the following classes as likely to do good
service in this respect: "Worthy men who have been degraded from
office, criminals who have undergone punishment; also, favorite
concubines who are greedy for gold, men who are aggrieved at
being in subordinate positions, or who have been passed over in
the distribution of posts, others who are anxious that their side
should be defeated in order that they may have a chance of
displaying their ability and talents, fickle turncoats who always
want to have a foot in each boat. Officials of these several
kinds," he continues, "should be secretly approached and bound to
one's interests by means of rich presents. In this way you will
be able to find out the state of affairs in the enemy's country,
ascertain the plans that are being formed against you, and
moreover disturb the harmony and create a breach between the
sovereign and his ministers." The necessity for extreme caution,
however, in dealing with "inward spies," appears from an
hist