35. For T’oegye’s disagreements with Zhu Xi, see Tomoeda Ryūtarō, “Yi T’oegye and Chu Hsi: Differences in Their Theories of Principle and Material Force,” in The Rise of Neo-Confucianism in Korea, ed. William Theodore de Bary and JaHyun Kim Haboush (New York: Columbia University Press, 1985), 243–260.

36. For details, see Smith, The I Ching: A Biography, 143–145.

37. For additional details, see Smith, The I Ching: A Biography, 146–147. I would like to express here my appreciation to the librarians and staff at the Gyujanggak Library of Seoul National University for providing access to this and other valuable Korean works on the Changes.

38. For a convenient overview, consult Choi, A Modern History of Korean Philosophy, 149–190.

39. Smith, The I Ching: A Biography, 147–148.

40. The literature on Tasan in Asian and Western languages is enormous. For a useful overview in English, see Mark Setton, Chŏng Yagyong: Korea’s Challenge to Orthodox Neo-Confucianism (Albany: State University of New York Press, 1997); and the introductory material in Hung-kyong Kim, The Analects of Dasan: A Korean Syncretic Reading (Oxford: Oxford University Press, 2016), 1–32.

41. I have been inspired and guided by Yung Sik Kim’s many valuable writings on Korean approaches to the Changes, including “Western Science, Cosmological Ideas, and Yijing Studies in Seventeenth- and Eighteenth-Century Korea,” Seoul Journal of Korean Studies 14 (December 2001): 299–334. See also Kim’s “Chŏng Yak-yong on Yijing Divination,” in Coping with the Future: Theories and Practices of Divination in East Asia, ed. Michael Lackner (Leiden: Brill, 2017), 345–365.

42. Chŏng Yagyong 丁若鏞 (a.k.a. Tasan [茶山]) (1762–1836), Yŏyudang chŏnsŏ 與猶堂全書 (Complete works from the Yŏyu Hall) (Seoul: Kyŏngin Munhwasa, 1989), I.18.5b [示二子家誡]. Tasan also produced several other works on the Yijing, including a long and highly personal draft essay on the classic titled Yŏk’ui 易義 (The meaning of the Changes). See Yŏyudang chŏnsŏ poyu 與猶堂全書補遺 (Supplement to the Complete Works from the Yŏyu Hall) (1974; repr. Seoul: Kyŏngʾin Munhwasa, 1989), 697–765.

43. In English, see Bang In, “The Philosophy of Change in Chông Yak-yong’s Zhouyisijian,” Korea Journal 28 (1988): 21–33; and “The Aspect of Dialectic Philosophy in Dasan Jeong Yag-yong’s Exposition of Yijing,” The Review of Korean Studies 9, no. 4 (December 2006): 169–188.

44. Yŏyudang chŏnsŏ, II.45.1a ff. [易學緖言].