Just as the Dīghanikāya begins with the complex and demanding Brahmajālasutta, the Majjhima opens with one of the most abstruse discourses in the entire canon. It examines the ways that the process of perception and identification evolves with progress on the path. It was translated, together with its commentary and extensive analysis, by Bhikkhu Bodhi as The Discourse on the Root of Existence. The commentarial background is also found in the Mūlapariyāya Jātaka (Ja 245). The commentary connects this sutta with the Gotamakacetiyasutta (AN 3.125), but there is no internal evidence to support this.

Ukkaṭṭhā, near Sāvatthī, is mentioned only rarely, and always in the context of extraordinary teachings and events that emphasize the cosmic grandeur of the Buddha against the brahmins, likely because it was the home of the prominent Kosalan brahmin Pokkharasāti (DN 3:1.2.1, DN 14:3.29.1, MN 49:2.1).

The pattern of this discourse answers to such passages as Bṛhadāraṇyaka Upaniṣad 3.7, where Yājñavalkya expounds a series of principles in relation to which the “immortal self” is conceived. The commentary says that this discourse was delivered to a group of former brahmins who had become conceited when they learned the Buddha’s teaching. While the text certainly responds to ideas and methods of Brahmanical texts, that interpretation is not supported by the text.

In his third discourse, speaking to Brahmanical ascetics, the Buddha reframed the “all” as the experience of the six senses (SN 35.28). The distinctive “conceiving” pattern of this sutta is therefore also applied to the “all” of the six senses (SN 35.30:1.19, SN 35.90:3.7). More broadly, the same pattern is also applied to the “aggregates, elements, and sense fields” (SN 35.31:1.21, SN 35.91:4.1). | The meaning of “root” is clarified later (MN 1:171.4) as “taking pleasure”, i.e. craving, which is the “root” of suffering.

An “unlearned ordinary person”, who has not realized any of the stages of the noble path, is contrasted with one who has entered the path. | “Noble one” (ariya) loosely conveys the sense “cultured” or “civilized”; it is a term for the inheritors of the Aryan culture that originated among the proto-Indo-European peoples of the central Asian steppes. | “True person” (sappurisa) indicates one who is authentic and genuine in their realization of the truth, and hence is virtuous and good. Both “noble one” and “true person” are technical terms referring to any person who has at least entered the path to stream-entry.

Although their perception (saññā) is accurate, to perceive something “as” something is to recognize it filtered through memory and concepts learned in the past, a subtle pre-processing that interprets present experience in light of expectations and desires. | The ending -to here and throughout is the “ablative of perspective”, which is used with verbs of cognition to express the idea of seeing something in a certain light; for example, one contemplates the body “as impermanent” (MN 74:9.1).

To “conceive” or “imagine” (maññati) is, according to the commentary, to think in terms of a “self”, proliferating experience through craving, conceit, or views until it is constructed for me. This usage draws upon such passages as Bṛhadāraṇyaka Upaniṣad 4.3.20, where due to ignorance, a person “imagines” in a dream the fearful things they saw when awake, or at the highest level, “imagines I am this all” (ahamevedaṁ sarvo’smīti manyate). | Each of the five phrases takes the “perception of earth as earth” and conceives, imagines, or construes that perception in progressively more differentiated and objectified ways, until it becomes something that is owned and enjoyed.

“Complete understanding” (pariññā) is the understanding of the arahant that permanently cuts through all delusions and conceits.

The sutta proceeds through the four main physical elements or properties before proceeding to beings and then various deities. The difference between these things is not as clear-cut as one might think. The elements were worshiped as gods, while the gods were often anthropomorphized natural phenomena such as the sky (deva) or the sun (“streaming radiance”). To identify with a material element is to share the essence of a powerful force of nature. | A similar list, but with fewer items, is found starting at MN 49:11.1.

“Creatures” (bhūta) can refer to any living being, including humans and animals, as well as invisible entities such as ghosts.

“Gods” (deva) or “deities” (devatā) are terms for the many divine entities of ancient Indian belief. Some were inherited from the old Vedic theology, while others reflect local customs and beliefs. All are impermanent and subject to suffering.

Pajāpati (“progenitor”) was the lonely god of creation (“Let Prajāpati generate progeny for us”, Rig Veda 10.85.3). The heat of his fervent exertions (tapas) created the world and all things in it (Śatapatha Brāhmaṇa 6).

Brahmā is also regarded as a creator, but in the sense of the underlying divine force that sustains the life of the cosmos. In Buddhism, several individual Brahmās appear, depicted as high deities who achieved their status due to the practice of first jhāna in a past life.

This and the next two are higher Brahmā realms. Beings in this realm are sometimes called “gods” (devā). They achieved their status through the second, third, and fourth jhānas respectively. Later Brahmanical texts mention a class of Ābhāsvara deities, but it does not appear to be a Vedic concept.

“Universal beauty” is subhakiṇha. Subha is “beauty, radiance”. Kiṇha is “universal, entire, total” (= Sanskrit kṛtsna); the same word is the basis for the meditation on “universals” (kasiṇa). The concept appears to be Buddhist, but we find a precedent when Yājñavalkya says that, just as salt is “entirely” salty, the Self is an “entire mass of consciousness” (kṛtsnaḥ prajñānaghana eva, Bṛhadāraṇyaka Upaniṣad 4.5.13).

The gods of “abundant fruit” (vehapphala; Sanskrit bṛhatphala) do not appear in Brahmanical literature, but bṛhat is a common descriptor of divinity. See eg. the Vedic god Bṛhaspati, identified with the planet Jupiter, or Rig Veda 9.107.15, which describes Soma as ṛtam bṛhat, “vast and true”.

“Vanquisher” (abhibhū) is an epithet of Brahmā (MN 49:5.2) that was appropriated for the Buddha (AN 4.23:5.1). In Rig Veda 8.97.10 it is an epithet of Indra, but it is not a regular name for a deity in either Buddhism or Brahmanism. Here it appears to be the name of the highest of the Brahmā gods.

Here begins the series of realms associated with the practice of formless meditations. These were practiced by the most advanced non-dualist Brahmanical teachers before the Buddha, who identified such experiences with the highest Self that is the cosmic divinity. The Buddha adopted the practices as part of the development of meditation, divesting them of metaphysical significance.

“Space” (ākāsa) is a principle of deep significance in the Upaniṣads, yet it is ultimately a lesser manifestation of the Absolute (Bṛhadāraṇyaka Upaniṣad 3.8.7; Taittirīya Upaniṣad 2.1.1; Chāndogya Upaniṣad 7.12).

“Infinite consciousness” is identified with the highest Self by Yājñavalkya at Bṛhadāraṇyaka Upaniṣad 2.4.12.

Taught by the Brahmanical sage Āḷāra Kālāma at MN 26:15.13.

Taught by the Brahmanical sage Uddaka Rāmaputta at MN 26:16.13.

Now the discourse introduces the “epistemic tetrad”—the seen, heard, thought, and known—which describe the means of knowing spiritual truths (see also note on SN 24.1:4.11). This framework was adopted from Yājñavalkya, for whom it is the Self that must be seen, heard, thought, and known (Bṛhadāraṇyaka Upaniṣad 1.4.7, 2.4.5, 4.5.6; cf. Chāndogya Upaniṣad 3.13.7). Yet the Absolute Self is “the unseen seer, the unheard hearer, the unthought thinker, the unknown knower” (Bṛhadāraṇyaka Upaniṣad 3.4.2, 3.7.23, 3.8.11, 4.3.31), the divinity that is ancient and primordial (4.4.18). It is through inference or understanding that one can learn to see, hear, think, and know that which is unknown (Chāndogya Upaniṣad 6.1.3), and which comprises one’s spiritual understanding (Chāndogya Upaniṣad 6.4.5).

While the “sight of ascetics” is regarded as a blessing (Snp 2.4:10.2), taking the “seeing” of a holy person as a standard of truth is a mistake (Snp 4.4). For Vedists, seeing can also refer to the Self which is beheld in a dream (Bṛhadāraṇyaka Upaniṣad 4.3.9), where things are revealed in a person’s own light (4.3.14).

This refers to teachings that are “heard” or learned by being passed down in oral tradition through a lineage of teachers. Knowledge heard from a teacher is said to lead to the goal (Chāndogya Upaniṣad 4.9.3). These are the Vedic scriptures (śruti) that were believed to have been “heard” or transmitted by divine inspiration. Buddhist suttas are marked with the phrase, “So I have heard”. No scripture, however, is infallible (MN 76:25.2).

Muta means “(what is) thought”, but is often mistranslated as “sensed”, a meaning that does not occur in the early texts. Chāndogya Upaniṣad 7.5.1 explains that “thought” (there, citta) is the basis of the Vedic mantras. Philosophical thought, like scripture, is fallible (MN 76:27.3), but people get attached to their theories (Snp 4.5).

The “known” (viññāta) is that which is cognized with consciousness (viññāṇa). For the Vedists this has the sense of “understanding” of the various branches of learning (Chāndogya Upaniṣad 7.7.1). It can also mean the states of expanded consciousness in deep meditation as indicated in the expanded “epistemic heptad” (SN 24.1:4.11). Even such states are not immune to misinterpretation (eg. MN 136:9.1, DN 1:1.31.1).

Perception of “oneness” (ekatta) sees the world as manifold reflections of an underlying unity. Arising from meditative experience or philosophical reflection, it is associated with the non-dual schools of Brahmanism. Īśa Upaniṣad 7, for example, speaks of “contemplating the oneness” (ekatvam anupaśyataḥ) of all creatures with the supreme soul. Yājñavalkya said in the state of non-differentiation the Self “becomes clear as water, one, the seer without a second; this is the Brahmā realm” (Bṛhadāraṇyaka Upaniṣad 4.3.32: salila eko draṣṭādvaito bhavati, eṣa brahmalokaḥ).

“Diversity” (nānatta) is the opposite fallacy to “oneness”; based on the diversity of sense experience, it interprets the world as irreducibly manifold. An example would be the Jains, who believed the world was made up of countless separate entities, a view criticized in Māṇḍūkya Upaniṣad 3.13 (nānātvaṁ nindyate). Both these fallacies take a particular mode of perception which is true in certain respects and make it into a metaphysical absolute.

The “all” is another critical term in the Upaniṣads, representing the totality of creation as an expression of divinity. See eg. Chāndogya Upaniṣad 7.25.2, “the self is all this” (ātmaivedaṁ sarvamiti), or Bṛhadāraṇyaka Upaniṣad 2.5.19, “this self that experiences all is divinity” (ayam ātmā brahma sarvānubhūḥ).

It is puzzling to see “extinguishment” (nibbāna; Sanskrit nirvāṇa) here, as it is the end of conceiving. The similar sequence at MN 49:23.1 culminates with “all”. Three interpretations: (1) Simple textual error. Of the three Chinese parallels, EA 44.6 mentions nibbāna here, while MA 106 and T 56 do not. If two separate texts have the same error, it predates the separation between the schools, or arose later through contamination. (2) The five kinds of “extinguishment in the present life”. These are false liberations believed by sectarians (DN 1:3.19.1). The commentary says they are meant here, but it seems unlikely, given that below the stream-enterer is enjoined to not identify with nibbāna, whereas they have already dispelled such misconceptions of the path. (3) An unenlightened person’s misconception of the Buddhist goal. At least some ancient Buddhists read it this way, as this passage is quoted in an Abhidhamma discussion as to whether the deathless as an object of thought can be a fetter (Kathāvatthu 9.2). The Theravāda commentary, rejecting this, says it was the view of the Pubbaseliyas, a branch of the Mahāsaṅghikas.

A “trainee” (sekha), who has realized stream-entry, once-return, or non-return, has had a vision of the path and Nibbāna. Yet since they have not fully relinquished the fetters that bind them to transmigration, they continue to deepen their practice of the noble eightfold path. Their “direct knowing” (abhiññā) is purified by the twin powers of samatha and vipassanā meditation, rather than “perception” (saññā), which is filtered through the five hindrances and other cognitive distortions. This distinction between perception and higher awareness (vijñāna or prajñāna) was first made by Yājñavalkya (Bṛhadāraṇyaka Upaniṣad 2.4.12 and 4.5.13).

The sutta depicts progress through the path in three grammatical modes. The ordinary person conceives; the trainee ought not conceive; the perfected one does not conceive. This echoes the “three rounds” of the first sermon (Dhammacakkappavattanasutta, SN 56.11): “there is” suffering; suffering “should be understood”; suffering “has been understood”.

The stream-enterer has not necessarily had personal experience of all these meditation states and realms of existence. Yet they “directly know” dependent origination, and hence understand that all such states are conditioned, impermanent, and included within the round of transmigration.

The “perfected one” is the arahant, literally “worthy one”, who is the Buddhist spiritual ideal. Their direct knowing is so powerful that it has cut through all fetters binding them to transmigration.

The text repeats the passage on the perfected one three times, emphasizing the ending of greed, hate, and delusion respectively.

The Buddha is an arahant, and he shares his fundamental understanding with other arahants. Yet the suttas elevate his understanding as the one who discovered the path.

To “completely understood to the end” is a phrase unique to this sutta. It implies that, while other arahants understand phenomena to the extent necessary for release, the Buddha understands all phenomena without exception.

This clarifies an ambiguity in the phrase “approve” (or “delights”, “relishes”, (abhi)-nandati). This can have a positive sense, as the audience normally “approves” the Buddha’s teachings (but see the end of this sutta). Here, however, the Buddha clarifies that he is using “approve” in the sense of craving, as it is found in the standard definition of the second noble truth (SN 56.11:4.4).

With these lines the Buddha connects the teachings of this sutta with dependent origination. He employs a similar strategy at the end of the Brahmajālasutta.

That they “did not approve” (na abhinanduṁ) is confirmed in the commentary and in the parallel at EA 44.6, which explains that the mendicants did not understand the discourse. Alternatively, some modern interpreters (Bodhi, Ñāṇananda), relying on the commentarial background explanation, suggest that the problem was that they understood it all too well and were not happy that their beliefs were challenged. These explanations, however, do not take into account the centrality of “approval” (nanda)—it is literally the “root” that lends the discourse its title. Given that an arahant does not “approve” even Nibbāna, and that “approval” is the root of suffering, is it any wonder that the audience did not “approve” the teaching? It is not that they did not understand, nor that their understanding threatened their egos, but that they understood so well that they received the teaching with perfect equanimity. Elsewhere the Buddha urged that one should “neither approve (abhinandati) nor dismiss” a teaching (AN 4.180:2.5 = DN 16:4.8.4, DN 29:18.4, MN 112:3.1). The normal response, where the audience approves a teaching with pleasure, is meant in a conventional sense, whereas this sutta shows how for an arahant all such responses are transcended.