Does the manas only discriminate changing and impermanent mental objects?

The scope of what the manas discerns is extremely broad; it can discern all dharmas. Regardless of whether these dharmas change or not—some dharmas remain unchanged for a long time, and the manas can still discern them; even minute, unchanging dharmas can be discerned. If there were dharmas that the manas could not discern, then the six consciousnesses could not arise to carry out further detailed and specific discernment.

The manas discerns not only the dharmas within the supreme faculties (indriya), but also the dharmas outside the supreme faculties. It can discern all the realms of the six sense objects; otherwise, it could not give rise to the six consciousnesses. After discerning form objects (rūpa-viṣaya), if it wants to discern specifically what color and what object it is, the eye consciousness and mind consciousness will arise; after discerning sound objects, if it wants to know what the sound is, the ear consciousness and mind consciousness must arise to discern it specifically. The same applies to the other objects of form, sound, smell, taste, touch, and dharmas.

The manas can also discern the coarse five sense objects. For example, if there are colorful flowers in front of one, and the manas is interested in the purple flowers, it will cause the eye consciousness and mind consciousness to arise upon the purple flowers and discern them with focused attention. The more interested the manas is, the longer the discernment lasts and the more focused it becomes. That the eye consciousness and mind consciousness can concentrate on admiring violets for an hour or two shows that the manas is very interested in the violets, continuously contacting the violets and continuously discerning them; otherwise, the eye consciousness and mind consciousness would vanish and no longer appreciate the violets. The same is true for the other sense objects.

Why insist on saying that the manas only discerns changing, fluctuating mental sense objects (dharma-viṣaya)? It can discern unchanging mental sense objects as well as all six sense objects; otherwise, it would lose its function of awareness and vigilance, and the six consciousnesses could not arise.