First Moon, Second Moon, Shadow Moon

In the Śūraṅgama Sūtra, the World-Honored One defines the second moon as the moon formed by pressing the eye; it is more real than the reflected moon. The wondrous essence luminous mind spoken of in the Śūraṅgama Sūtra refers to the substance of the eighth consciousness, which is the first moon, also the original moon. The functions arising from the substance of the eighth consciousness are the second moon, which exists in dependence upon the substance. For example, the seeing nature and Buddha-nature by which the eighth consciousness sees all dharmas through the six faculties is the second moon, not the function of the substance of the eighth consciousness. The operation of the mental factors (caittas) of the eighth consciousness, the discerning function toward all dharmas, is the second moon, not the function of the substance of the eighth consciousness. The substance of the eighth consciousness, the first moon, cannot be seen by anyone, including the Buddha; one can only see the second moon and the reflected moon.

The reflected moon is all the illusory dharmas manifested by the eighth consciousness through the second moon, by employing karmic seeds and the seeds of the seven great elements. This includes material form (rūpa-dharma), mental dharmas, and mental factors (caittas).