Why Can Manas and Vijñāna Mutually Convey Intentions?

For instance, when the manas (mental faculty) desires to eat, the Tathagatagarbha (Buddha-nature) complies with the intention of manas, giving rise to consciousness (vijnana). Manas then conveys to consciousness the task of discriminating the various dishes before it. Among these dishes, manas selects what it prefers to eat. Consciousness comprehends the intent of manas. After consciousness discriminates, manas also comprehends the intent of consciousness. The two can communicate with each other instantaneously. However, when manas discriminates dharmas (phenomena) from past lives and conveys them to consciousness, consciousness is unable to comprehend them, or only understands a little. Why is this? Because without having experienced the past lives, there is no memory, and thus discrimination is impossible.

Manas determines to discriminate the various dishes to decide which one to eat. When consciousness arises, it discriminates on behalf of manas. After consciousness discriminates and judges the characteristics of each dish, it conveys this information to manas. Once manas is informed, it decides what to eat. It is also possible that consciousness, relying solely on observation alongside the eye-consciousness, cannot discriminate comprehensively. Manas then decides to taste a little. Consequently, the tongue-consciousness and nose-consciousness participate together in discrimination and judgment. After manas is informed, it knows which dish is delicious and to its liking, and thus eats heartily, avoiding the unpalatable ones.

These dishes can be directly contacted by consciousness and the five sense-consciousnesses (eye, ear, nose, tongue, body) in the present moment. Therefore, there are feelings (vedana), perceptions (samjna), and volitions (cetana), enabling judgment. Regarding dharmas from past lives, without supernatural powers (abhijna), the five sense-consciousnesses cannot contact them at all. Consciousness lacks the psychic power (mind-reading) and experience, and its wisdom is insufficient, thus it cannot know what is thought and intended in the mind of manas. If consciousness possesses great wisdom, it can clearly discriminate the dharmas thought, intended, or implied in the mind of manas.

Why can consciousness and manas convey intentions to each other? Because manas contacts the mental objects (dharmas), giving rise to consciousness. The three (manas, dharmas, consciousness) then combine in contact. Regarding mental objects, not only can manas discriminate them, but consciousness can also discriminate them, though the degree and clarity of discrimination may vary. During this process, consciousness and manas are also constantly in contact with each other; mind contacts mind. Naturally, they can mutually know each other's intentions, though the degree of knowing differs in depth and scope. As long as consciousness exists, it is necessarily in contact with manas. Therefore, their respective intentions can be transmitted and communicated anytime, anywhere. If the communication is poor, psychological dissonance occurs; if the communication is smooth, the mood is pleasant. This is somewhat analogous to the relationship between two people interacting.