Outer Feeling and Inner Feeling in the Mahāsatipaṭṭhāna Sutta

In the Great Mindfulness Sūtra, when the Buddha taught the contemplation of feeling, He spoke of two kinds of feeling: inner feeling and outer feeling. Outer feeling refers to the feeling of the mind consciousness that is easy to observe, especially the feeling of the mind consciousness with respect to the objects of the six sense-objects; inner 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 inner mind and the outer mind, and observe whether the inner mind and the outer mind are concentrated or scattered, expansive or narrow, surpassed or unsurpassed, concentrated or unconcentrated, liberated or not liberated. This shows that the inner 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 Hīnayāna 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 could not understand and realize, let alone Hīnayāna 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 hidden way.

The affliction of doubt includes inner doubt and outer doubt, and the elimination of doubt must be thorough and complete—it must certainly be the elimination of the manas's doubt. Therefore, the three fetters refer entirely to the fetters of the manas; only by eliminating the doubt of the manas are the three fetters severed. As for severing greed, only by 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. As for severing hatred, it must certainly be the elimination of the hatred of the manas for one to be a third-fruit person (Anāgāmin). As for severing delusion, it must certainly be the elimination of the deluded ignorance of the manas for one to transcend the three realms.

The Hīnayāna Buddhist sūtras are the easiest to understand, yet what person can truly comprehend the Hīnayāna Buddhist sūtras? Let alone the Mahāyāna sūtras—what person can truly understand them completely? Even having attained the fruit of arhatship, one still cannot completely trust one's own mind; wisdom is insufficient and understanding is not ultimate, so trusting it completely makes errors likely.

The Buddha-dharma is not fragmentary; it must be coherent and continuous from beginning to end, with all parts mutually supporting and explaining one another. When it comes to debating the Buddha-dharma, who is qualified to debate? What qualification do those of small faculties and small wisdom have to initiate a debate or participate in one?