_Surviving spies_, finally, are those who bring back news from the
enemy’s camp.
This is the ordinary class of spies, properly so called, forming a
regular part of the army. Tu Mu says: 生間者必取內明外愚形劣心壯趫健勁勇
閑於鄙事能忍饑寒垢耻者爲之 “Your surviving spy must be a man of
keen intellect, though in outward appearance a fool; of shabby
exterior, but with a will of iron. He must be active, robust,
endowed with physical strength and courage; thoroughly accustomed
to all sorts of dirty work, able to endure hunger and cold, and to
put up with shame and ignominy.” Ho Shih tells the following story
of 達奚武 Ta-hsi Wu of the Sui dynasty: “When he was governor of
Eastern Ch‘in, 神武 Shên-wu of Ch‘i made a hostile movement upon
沙苑 Sha-yüan. The Emperor T‘ai Tsu [? Kao Tsu] sent Ta-hsi Wu to
spy upon the enemy. He was accompanied by two other men. All three
were on horseback and wore the enemy’s uniform. When it was dark,
they dismounted a few hundred feet away from the enemy’s camp and
stealthily crept up to listen, until they succeeded in catching
the passwords used by the army. Then they got on their horses
again and boldly passed through the camp under the guise of
night-watchmen (警夜者); and more than once, happening to come
across a soldier who was committing some breach of discipline,
they actually stopped to give the culprit a sound cudgelling! Thus
they managed to return with the fullest possible information about
the enemy’s dispositions, and received warm commendation from the
Emperor, who in consequence of their report was able to inflict a
severe defeat on his adversary.” With the above classification it
is interesting to compare the remarks of Frederick the Great:[186]
“Es giebt vielerley Sorten von Spions: 1. Geringe Leute, welche
sich von diesem Handwerk meliren. 2. Doppelte Spions. 3. Spions
von Consequenz, und endlich 4. Diejenigen, welche man zu diesem
unglücklichen Hankwerk zwinget.” This of course is a bad
cross-division. The first class (“Bürgersleute, Bauern, Priesters,
etc.”) corresponds roughly to Sun Tzŭ’s “local spies,” and the
third to “inward spies.” Of “Doppelte Spions” it is broadly stated
that they are employed “um dem Feinde falsche Nachrichten
aufzubinden.” Thus they would include both converted and doomed
spies. Frederick’s last class of spies does not appear in Sun
Tzŭ’s list, perhaps because the risk in using them is too great.