Selected Discourses on the Sutra of the Father and Son: Part 3

Original text: What are the six bases of contact? Namely, the eye-base of contact perceives forms; the ear-base of contact perceives sounds; the nose-base of contact perceives scents; the tongue-base of contact perceives tastes; the body-base of contact perceives tangible objects; the mind-base of contact perceives mental objects.

Explanation: The World-Honored One said: What are the six bases of contact? It is the eye-base of contact that perceives forms. At the point where the eye-faculty and form-dust come into contact, eye-consciousness arises, enabling the perception of forms. At the ear-base, contact with sound-dust gives rise to ear-consciousness, enabling the hearing of sounds. At the nose-base, contact with scent-dust gives rise to nose-consciousness, enabling the smelling of fragrances, foul odors, and other miscellaneous scents. At the tongue-base, contact with taste-dust gives rise to tongue-consciousness, enabling the tasting of sour, sweet, bitter, spicy, and salty tastes. At the body-base, contact with tangible-dust gives rise to body-consciousness, enabling the perception of tangible objects. For example, contact with sunlight enables the perception of warmth; wind blowing against the body, the body contacting wind, enables body-consciousness to perceive coolness. This also includes bodily sensations such as lightness, comfort, hunger, thirst, fatigue, soreness, and exhaustion, which are all tangible-dust. At the mind-base, when the mind-faculty contacts mental-dust, mind-consciousness arises, enabling the discernment of all mental-object phenomena.

Original text: What are the eighteen mental investigations? When the eye perceives a form, either pleasant feeling arises, or unpleasant feeling arises, or one abides in equanimity. Similarly, each of the six faculties, upon contacting their respective objects, gives rise to these three [feelings]—pleasant and so forth. These are called the eighteen mental investigations.

Explanation: "Investigation" means observation, discernment, understanding, and sensation. For instance, after the eye-faculty contacts form-dust, when eye-consciousness and mind-consciousness discern the form-dust, if a pleasant or unpleasant mental state arises, or if one abides in an intermediate state of sensation that is neither pleasant nor unpleasant, three types of feelings appear. This constitutes a set of three realms for each faculty-dust-consciousness triad. The other five faculties—ear, nose, tongue, body, and mind—similarly, upon contact with their respective dust, give rise to consciousness. The conscious mind then produces sensations, generating either pleasant, unpleasant, or neither-pleasant-nor-unpleasant (equanimity) states of mind. This results in five sets of fifteen realms, which together with the first set make six sets of eighteen realms. After each faculty contacts its dust, there are three realms (faculty, dust, consciousness). The six faculties contacting the six dusts together constitute the eighteen realms, respectively generating the three feelings of pleasant, unpleasant, and neutral (equanimity). These are the eighteen mental investigations.