PART II INTRODUCTION 119or slave society. By that time the power of the slaveowners and the practice of
chattel slavery had been such a powerful aspect of Korean life that hardly any-
one could be expected to call it into question.
It was only when the demand for manpower for military service rose sharply
during the Japanese and Manchu invasions between 1592 and 1637 that the gov-
ernment began to relax the restraints against the manumission of slaves. Changes
in the economy that were set in motion in the first two centuries of the dynasty
- the expansion of agricultural production and the development of the market
and a partially monetized economy - worked to disrupt the earlier social struc-
ture by permitting a few slaves, who lived at some distance from the master and
functioned much like tenants, to accumulate sufficient wealth to purchase their
freedom or bribe the clerks to remove their names from the registers. The gen-
eral breakdown of morale and discipline made it easier for slaves to run away
from their villages, but significant decline in the numbers of slaves in the pop-
ulation was not achieved until the middle of the eighteenth century - a century
after the death ofYu H yongwon. It was partially as a consequence of this greater
sensitivity to the drawbacks of slave society in Korean society that a stimulus
was provided for Yu Hyongwon to undertake the first truly serious considera-
tion of the propriety of slavery in Korean society from a consciously Confucian
perspective.
THE CAUSES OF YANGBAN POWER: LEARNING FROM THE PAST
The purpose ofYu's scholarly investigations was to identify the main problem
with the ruling class of his own society and to find ways of rectifying it. His
individual chapters for the most part were divided in two, the first half copying
out material relevant to the specific institution under discussion, usually with-
out much comment, and the second half presenting Yu's proposals for reform,
sometimes accompanied by an occasional historical reference, argument. or anal-
ogy. The introductory sections often contain material that Yu did not apply to
his own reforms, but much of it did, and in any number of cases Yu simply adopted
policies and plans from past Chinese dynasties or statecraft writers, or sugges-
tions made by favored Korean officials without much change. The concluding
section of most chapters included Yu's own program for reforms for contem-
porary Korea, the locus of his most interesting and original propositions.
The overwhelming proportion of his reference materials came from Chinese
sources that were subdivided into two parts: the classics and materials covering
the period of antiquity in ancient China down through the Chou dynasty, and
historical references and policy statements made in the post-Chou age, the "later
age" (husc) that was equivalent to the world after the Fall from Grace brought
about by the Ch'in dynasty's destruction of classical Chou institutions.
Material from the Chou period provided models for and goals for emulation,
but Yu did not believe that there was any real chance of recovering the perfec-
tion of Chou times, or even of replicating Chou institutions exactly. In fact, he