232 SOCIAL REFORMcommoner population, probably because that was done by permitting manu-
mission either for the performance of meritorious military action or the pay-
ment of a grain contribution to the government.
Unfortunately, that measure was by no means the most radical and etJective
method of reform at the time because slaves had already been accepted into the
sog'o units of the army and were performing the function of both duty soldiers
and support taxpayers for the army. Since commoners began to be formally
excluded from the sog'ogun after 1736, the state had obviously responded to the
shortage of commoner male adults by expanding the use of private slaves to
replace them. By the mid-eighteenth century slaves may have accounted for 30
percent ofthe soldiers in the army, approximately the same percentage of slaves
in the total population.^96 To ease the tax burden on private slaves who had to
pay a support tax for duty soldiers since the private slaves also owed the per-
sonal tribute tax (sill 'go/lg) to their masters, the government set their tax rate at
half the rate for commoner support taxpayers, but few argued that the purpose
of reform was to make life easier for the slaves. 97
Nonetheless, the main reason used to justify the adoption of the matrilineal
rule first in [669, and finally in 1730, was the argument that there were too many
slaves and something had to be done to create more commoners. One might
deduce that the main reason why reform policy was restricted only to liberat-
ing the future offspring of commoner mothers and permitting a minimal num-
ber of slaves to buy their own freedom was not only that the power of the
slaveholding class and their domination of the government as high-ranking
bureaucrats was too great to overcome, but that the reformers themselves were
also members of that same slaveholding class and were reluctant to adopt any
radical policy that would severely damage those class interests. Since the matri-
lineal law was not adopted permanently until 173 I, it could not have had any
serious effects on the slave population until a generation later.
Yu HYONGWON's SOLUTIONS FOR SLAVERY
Chinese Precedent
Yu Hyongwon introduced his discussion of slavery in his usual fashion by inves-
tigating classical Chinese sources on the subject, but this alone was a departure
from the long tradition of beginning any treatment of Korean slavery with Kija's
law code. He began with The Rites of Chou, which revealed to him that under
the sage rule of the Chou kings the only legitimate form of slavery was the
enslavement of barbarian prisoners of war and criminals and their families and
who were employed by the government as official slaves. Although The Rites
of Chou did justify slavery, it did not legitimate private slavery.9R "There is no
case of any ordinary people who were made slaves" [italics mine ].9^9
Yu implicitly indicted the enslavement of non criminals as private slaves and,
in particular, the Korean system of hereditary slavery by which the innocent