The Principle of How Eye Consciousness and Mind Consciousness Discriminate Visual Objects

When the eye faculty's gross material faculty (rūpa-prasāda) comes into contact with external material sense-objects, it is actually not the eye faculty that captures the four great elements' subtle particles of the material sense-object, but the tathāgatagarbha. The eye faculty is like a video camera—merely a tool and a prop. Through the instrument of the eye faculty, the tathāgatagarbha captures the four great elements' subtle particles from the external material sense-object. After the tathāgatagarbha has captured these particles, they pass through the eye faculty, the eyeball, the vitreous body, and the visual transmission nerves, and then arrive at the supreme faculty (indriya) of the eye faculty located in the back of the brain, where the image of the external material sense-object is directly formed. Among these, colors belong to the manifest forms (sanidarśana-rūpa) of the material sense-object; the mental sense-object is the form included in the mental-object base (dharma-āyatana), which comprises visible form (saṃsthāna-rūpa), expressive form (vijñapti-rūpa), and non-expressive form (avijñapti-rūpa); these three together constitute the mental sense-object.

Because colors are relatively simple and uncomplicated, the eye consciousness can discern them rather quickly, whereas the mental sense-object is more complex, difficult to know and clearly identify, and therefore takes relatively longer to discern. In the first instant, after the manifest forms come into contact with the eye faculty, the tathāgatagarbha gives rise to the eye consciousness; in the second instant, after the manas comes into contact with the mental sense-object, the tathāgatagarbha then gives rise to the mind consciousness. This corresponds exactly to the relationship of the eye consciousness discerning in the first instant and the mind consciousness discerning in the second instant. Then the eye consciousness and the mind consciousness together discern the material sense-object, and what is thus discerned is the complete material sense-object (this is a matter occurring after the third instant).

Why must the eye consciousness first arise in the first instant to discern manifest forms, and only afterward can the mind consciousness discern visible form, expressive form, and non-expressive form? Because manifest forms must first be formed and exist first; only then can visible form, expressive form, and non-expressive form be displayed. These three kinds of material form are based on manifest forms. For example, among visible forms—large and small, square and round, long and short—without the colors of manifest forms as a foil, it would be impossible to represent large and small, square and round, long and short. Expressive form can only manifest by relying on manifest forms, taking manifest forms and visible form as its basis. Non-expressive form can only manifest by relying on manifest forms, visible form, and expressive form, taking manifest forms, visible form, and expressive form as its basis. Therefore it is said: manifest forms exist first, so the eye consciousness must first arise to discern manifest forms, and the mind consciousness arises afterward to discern the mental sense-object.