Why Must the Five Consciousnesses' Discernment of the Five Sense Objects Be Decided by the Manas?

Question: When my body itches, I can't help wanting to scratch it, but then I realize that this is all the body consciousness contacting the sense object—where is there any itch? Don't fabricate. So I stopped attending to that spot, and the itch immediately disappeared. If I continued to attend to it, the itch remained; then when I stopped attending again, the itch disappeared again. This went back and forth twice, with a slightly longer interval in between, and when I no longer attended to it, the itch completely disappeared. Did the itch truly disappear?

Answer: When the faculties and sense objects contact each other, consciousness arises; once consciousness is born, it discerns the sense-object realm; after discerning it, feelings arise—one feels cold, heat, touch, pain, itch, and so on—and afterwards the emotions of suffering, happiness, sorrow, joy, and neutral feeling are produced. This is the sequence of operation of the six sense bases (ṣaḍāyatana), contact, and feeling among the twelve links of dependent origination. Whether the faculties and sense objects contact each other is determined by the manas. For example, when the body itches, if the manas does not attend to the itchy spot and shifts its attention elsewhere, then the mind consciousness and body consciousness cannot arise at the itchy spot, the itch as a tactile sense object is not discerned, and feelings will not appear, so one does not know of the itch and does not feel it. This is the manas shifting its attention, causing the six consciousnesses not to arise at that spot and thus not to discern it—it is not that there is no itch. If the manas does not shift its attention, and the body faculty is in contact with the tactile sense object of the itch, the body consciousness and mind consciousness will arise and discern the tactile sense object of the itch, and one will feel itchy; afterwards the manas will choose to scratch, and so the body consciousness and mind consciousness will scratch the itch.

This shows that the manas is the consciousness that makes decisions: it governs the contact between faculties and sense objects, governs the arising, ceasing, coming, and going of the six consciousnesses, governs the discernment of the six consciousnesses, and governs bodily, verbal, and mental actions. At the same time, this also shows that whether the five faculties—eye, ear, nose, tongue, and body—should contact the five sense objects of form, sound, smell, taste, and touch is all decided by the manas, and the discernment of the five consciousnesses is also decided by the manas. Here a question arises: why does the manas govern the arising and discernment of the five consciousnesses? Why is the discernment of the five sense objects by the five consciousnesses decided by the manas? Since the manas can make such decisions, He must first have discerned the five sense objects before He could take up or reject them, make judgments and decisions. This shows that the manas can discern the six sense objects, and does not merely discern mental sense objects alone; otherwise, how could the five faculties contact the five sense objects, and how could the five consciousnesses arise?