Yulgok's theory of self-cultivation is developed, in general,
based on the neo-confucianism of Chengzi(程子) and Zhuzi(朱子)(程
朱性理學). It, however, is developed more elaborately, concretely
and constantly than Zhuzi in specific category and logics. That is
the characteristics of Yulgok's theory of self-cultivation and also
regarded as complement to or development of Zhuzi's
neo-confucianism. This thesis examined the characteristics of
Yulgok's theory of self-cultivation in its Relationship with Zhuxi(朱
熹), centering around Yipji(立志), restoration of qi(復其氣) and
Musil(務實).
It is common characteristics of Yulgok and Zhuxi to lay stress
on Yipji. However in laying stress on the importance of Yipji,
Yulgok put top priority on Yipji in all practice and behavior and
raised it to become the precondition of dispositional change. He
also understood Yipji and Seongeui(誠意) in an organic relationship,
trying to understand Yipji under the category of Seongeui from the
judgement that the key to fixing one's aim in life depends on
Seongeui. Unlike Yulgok, Zhuzi includes Yipji among the category
of Geogyung(居敬). This is difference between Zhuzi and Yulgok.
Yulgok recognizes dispositional change as the way of restoring
one's real nature. Yulgok takes up the 'restoration of qi'(復其氣) for
content of self-cultivation(修己) rather than the 'restoration of
xing'(復其性) that preceding Confucianists assert. Zhuzi argues that
restoration of one's real nature shall be acquired through
intellectual study of mind. Yulgok holds the logics that the process
of restoration of qi and process of restoration of xing are unified
ones based on Yigijimyo(理氣之妙), and maintains restoration of qi,
that is, restoration of one's real nature through dispositional
change. This is characterized by strong emphasis of Musil(務實) in
that Yulgok is more realistic than Zhuzi and grasps the root of an
issue and practices.
Yulgok emphasizes Silsim(實心) more than Zhuzi and develops
the theory of self-cultivation based on Musil that one does Silgong
(實功) in Silsim to get an actual effect(實效). This shows that the
feature of Yulgok's practical philosophy, trying to conduct what
is practical facing the reality, is reflected to the theory of
self-cultivation as ikt is. This Musil spirit goes through the general
neo-Confucianism of Yulgok and lays the foundation of Silhak(實學)
for future generations.
Though not escaping the frame of traditional Confucianism, the
neo-Confucianism of Yulgok shows the characteristics unique to
Yulgok that exceeds preceding Confucianists in terms of its
development of theory and logics. This might be the characteristics
of Yulgok's philosophy as well as Korean neo-Confucianism.