The significance of knowledge lies in its relation to objects as truth. According to Chih-i, with knowledge, truth can be manifested, for knowledge points to the place where truth resides. With the manifestation of truth, knowledge is entitled to be subtle. In view of the fact that they are complementary to each other as one entity, any one of these two categories is indispensable. Chih-i asserts:

“The ultimate principle [truth] is abstruse and profound, and it cannot be manifested without knowledge. [Although] knowledge is capable of knowing the place [where truth resides], it would not be merging without objects [as truth]. Since objects [as truth] are merging and subtle, knowledge is also entitled to be merging and subtle.” (Vol. 2, Page 132-133)