The Hidden Mental Factors (Caittas) of the Manas

When the Buddha taught the contemplation of feeling in the Mahāsatipaṭṭhāna Sūtra, he spoke of two kinds of feeling: internal feeling and external feeling. External feeling refers to the feeling of the mind consciousness, which is easy to observe—especially the feeling of the mind consciousness regarding the objects of the six sense-objects. Internal feeling refers to the feeling of the manas, which is hidden more deeply and is not easy to observe. Although the vast majority of people cannot distinguish between the mind consciousness and the manas, the deep mental activities of the mind can still be perceived and observed, as long as the mind is very subtle and meticulous.

When the Buddha taught the contemplation of mind, he said that in observing the mind, one should observe the afflictions of greed, hatred, and delusion in the internal mind and the external mind, and observe whether the internal mind and the external mind are concentrated or scattered, expansive or narrow, surpassed or unsurpassed, concentrated or unconcentrated, liberated or not liberated. This shows that the internal mind, the manas, has the afflictions of greed, hatred, and delusion, can be concentrated or unconcentrated, and can be liberated or not liberated. This proves from the Nikāya sūtras that the manas possesses these mental factors, even though the World-Honored One did not state it explicitly. Because the dharma of the manas is something that even Mahāyāna disciples cannot understand and realize, let alone Śrāvakayāna disciples being able to deeply and correctly understand the dharma of the manas, the World-Honored One had no choice but to teach the mental factors of the manas in a concealed manner.

Regarding the affliction of doubt, there is internal doubt and external doubt; when doubt is severed, it must be severed completely and ultimately, which necessarily means severing the doubt of the manas. Therefore, the three fetters refer entirely to the fetters of the manas; only by severing the doubt of the manas are the three fetters severed. By severing greed—severing the greed of the manas—can the mind correspond with the devas of the form realm and be reborn in the form realm heavens. Severing hatred must mean severing the hatred of the manas; only then is one a third-fruit person (Anāgāmin). Severing delusion must mean severing the delusive ignorance of the manas; only then can one transcend the three realms.

The Śrāvakayāna sūtras are the easiest to understand, yet how many people can truly comprehend the Śrāvakayāna sūtras? Let alone the Mahāyāna sūtras—how many people can truly understand them completely? Even having attained the fruit of arhatship, one still cannot completely trust one's own mind; when wisdom is insufficient and one's understanding is not ultimate, fully trusting it easily leads to errors.