The Interaction Between the Aggregate of Perception and the Aggregate of Volitional Formations

Question: It is said that merely hearing about a plum, without eating it, makes the mouth water with sour saliva. What is the reason for this?

Answer: When the World-Honored One speaks of this passage in the Śūraṅgama Sūtra, it is used as a metaphor to illustrate the illusory and unreal nature of the aggregate of perception (saṃjñā). The aggregate of perception belongs to the knowing and grasping nature of the conscious mind, as well as the various mental activities of the mind consciousness, such as thoughts and concepts. Hearing about a sour plum means knowing the sour plum, and subsequently giving rise to deliberation and thought in the mind—all of this is the aggregate of perception; the sour saliva flowing in the mouth is the aggregate of formations (saṃskāra). The fact that the aggregate of perception leads to the arising of the aggregate of formations shows that body and mind are closely connected and mutually influence each other. The body can exert influence upon the conscious mind, and the conscious mind can also exert influence upon the body. The changes and operations of the conscious mind can affect the body, prompting the body to undergo changes.

The three transforming consciousnesses—tathāgatagarbha, the manas (seventh consciousness), and the six consciousnesses—in combination can give birth to and change all dharmas. The matter of hearing about a plum is produced by the three transforming consciousnesses working in combination, and the phenomenon of sour saliva flowing in the mouth is also produced by the three transforming consciousnesses working in combination. In these two phenomena, the tathāgatagarbha is the same one, the manas is the same one, and the sixth consciousness is the same one. Moreover, within the aggregate of perception there are the functions of these three consciousnesses, and within the aggregate of formations there are also the functions of the three consciousnesses, and the mental sense-objects cognized by the three consciousnesses are likewise the same. Therefore, the aggregate of perception can interconnect with the aggregate of formations, and the aggregate of perception can influence the aggregate of formations. Thus, hearing with the ear and thinking in the mind can cause the body faculty to produce sour saliva in the mouth.

Based on past experiences, the mind consciousness knows that plums are sour. Having eaten sour things before and having had such experiences, the mind has the reaction of sourness. These experiences have already been stored as seeds in the tathāgatagarbha. When someone speaks of a plum, the ear faculty and the manas simultaneously attend to that sound, and the ear consciousness and the mind consciousness simultaneously discern its meaning. The manas, through the tathāgatagarbha, then transmits the past information related to plums, and this information, through the manas and the mind consciousness, exerts an influence upon the body, and the sour saliva flows out.