This is part of an ongoing glossary of terms relating to the Book of Dzyan.

“Extracts are given from the Chinese, Tibetan, and Sanskrit translations of the original Senzar Commentaries and Glosses on the Book of Dzyan— . . . Thus, were one to translate into English, using only the substantives and technical terms as employed in one of the Tibetan and Senzar versions, Verse 1 would read as follows : . . . alone Tho-og Yinsin in night of Sun-chan and Yong-grub (Parinishpanna), . . .” (The Secret Doctrine, vol. 1, p. 23).

yinsin, yin-sin, yin sin, yih-sin, yi-hsin. The word is printed as Yinsin in The Secret Doctrine 1.23; Yin-Sin in SD Würzburg, p. 143, and in SD 1.635; Yin Sin in Mahatma Letter #15 2nd ed.; Yin-sin in ML #15 3rd ed. and chron. ed.; Yih-sin in ML #59 2nd ed.; Yi-hsin in ML #59 3rd ed. and chron. ed. This Chinese word was adopted from yih-sin in Samuel Beal’s 1871 Catena of Buddhist Scriptures from the Chinese, pp. 373, 393, 98 fn. (the change of yih-sin to yin-sin is an obvious scribal or typographical error, mistaking an “h” for an “n”). Beal’s early spelling came to be standardized as i-hsin in the once commonly used Wade-Giles system of writing Chinese words in Roman letters, and as yixin in the now more standard pinyin system. Beal understood it as the “universally diffused essence” (pp. 11, 12, 13, 14, 29, 143-144, 340, 352, 373), and the “one form of existence” (p. 373). These phrases were used in the Mahatma letters to define it.

            This Chinese term translates the Sanskrit term eka-citta, meaning the “one mind.” The teaching of the “one mind” is presented in the Buddhist scripture known in the west as The Awakening of Faith (translated by Yoshito S. Hakeda, 1967), Sanskrit Mahāyāna-śraddhotpāda, Chinese Dasheng qixin lun. It is there taught as being the all, saying that (Hakeda, p. 28): “This Mind includes in itself all states of being of the phenomenal world and the transcendental world.” Further, that (Hakeda, p. 31): “the principle of One Mind has two aspects. One is the aspect of Mind in terms of the Absolute (tathatā; Suchness), and the other is the aspect of Mind in terms of phenomena (samsara; birth and death). Each of these two aspects embraces all states of existence. Why? Because these two aspects are mutually inclusive.” The first aspect (as suchness, tathatā) is the one mind as it is in itself, described as the dharma-dhātu (“element of attributes” or “realm of phenomena”), and as being unborn and imperishable (Hakeda, p. 32). As the tathāgata-garbha (“buddha-matrix” or buddha-nature) the one mind is the ground of saṃsāra (Hakeda, p. 36), birth and death, the production and cessation of the manifested cosmos. The tathāgata-garbha has been understood by different commentators on this text as the one mind itself, the first aspect, or as production and cessation, the second aspect (Princeton Dictionary of Buddhism, under yixin). The second aspect, birth and death or production and cessation, is the one mind as the ālaya-vijñāna, the storehouse consciousness (Hakeda, p. 36) or foundational consciousness. The ever-changing ālaya-vijñāna carries the seeds (bīja) of future results (phala) produced by all actions (karma), and thus produces the manifested cosmos. The cosmos, often referred to as the three worlds or the triple world (traidhātuka), operates by way of the twelvefold chain of causation or becoming (the twelve nidānas of dependent origination, pratītya samutpāda). The teaching of the one mind and its two aspects is very succinctly put in a famous statement from the Daśabhūmika-sūtra, for which we have the original Sanskrit in both prose and verse. These two Sanskrit formulations are given here, along with my English translation:

citta-mātram idaṃ yad idaṃ traidhātukam | yāny apīmāni dvādaśa bhavāṅgāni tathāgatena prabhedaśo vyākhyātāni tāny api sarvāṇy eka-citta-samāśritāni |

(Ryuko Kondo ed., p. 98; Johannes Rahder ed. has eva instead of eka, copied in the P. L. Vaidya ed.).

“This triple world is only mind. Also these twelve limbs of becoming that were explained individually by the Buddha, all those, too, are based on the one mind.”

te citta-mātra ti traidhātukam otaranti api cā bhavāṅga iti dvādaśa eka-citte |

(Rahder/Susa ed., p. 53, verse 16; Kondo ed., p. 108, verse 6; Vaidya ed., p. 87, verse 16).

“They comprehend that the triple world is only mind, and also that the twelve limbs of becoming are within the one mind.”

References: “Nor can it well be called force since the latter is but the attribute of Yin Sin (Yin Sin or the one “Form of existence,” also Adi-Buddhi or Dharmakaya, the mystic, universally diffused essence) when manifesting in the phenomenal world of senses, namely, only your old acquaintance Fohat. . . . The initiated Brahmin calls it (Yin Sin and Fohat) Brahman and Sakti when manifesting as that force.” (Mahatma Letter #15, 2nd ed. p. 90, 3rd ed. pp. 88-89, chron. ed. #67, p. 181).

“In symbology the central point is Jivatma (the 7th principle), and hence Avalokitesvara, the Kwan-Shai-yin, the manifested “Voice” (or Logos), the germ point of manifested activity; hence, in the phraseology of the Christian Kabalists, “the Son of the Father and Mother,” and agreeably to ours—”the Self manifested in Self—Yih-sin, the “one form of existence,” the child of Dharmakaya (the universally diffused Essence), both male and female. Parabrahm or “Adi-Buddha” while acting through that germ point outwardly as an active force, reacts from the circumference inwardly as the Supreme but latent Potency.” (Mahatma Letter #59, 2nd ed. p. 346, 3rd ed. pp. 340-341, chron. ed. #111, pp. 378-379).

Compare Beal’s Catena, p. 373: “So again, when the idea of a universally diffused essence (dharmakaya) was accepted as a dogmatic necessity, a further question arose as to the relation which this “supreme existence” bore to time, space, and number. And from this consideration appears to have proceeded the further invention of the several names Vairochana (the Omnipresent), Amitâbha (for Amirta [sic for Amrita]) the Eternal, and Adi-Buddha (yih-sin) the “one form of existence.””

Beal’s Catena, p. 11: “The whole of these systems again he includes within one universally diffused essence, which, for want of a better word, is called the “Heart,” but which, in fact, corresponds to the soul of the universe, the all-pervading Self or the “All in all” of pure Pantheism.”