Mutual Inclusion, and What the Three Terms Mean

T1606 states the logic plainly: the aggregate of form already subsumes all ten form-elements; the dharma element already subsumes itself (feeling, formations, and the eight unconditioned dharmas); and the mental-faculty sense field already subsumes all seven consciousness-elements. Nothing in the entire eighty-item spread of aggregates, elements, and sense fields falls outside these three — which is exactly why "three categories" (三法) is the name this treatise's very first chapter gives itself.

The four embryonic stages named here — kalala (a translucent, curdled droplet), arbuda (a soft, swelling mass), and peśī (a firm, oblong mass, the "closed" stage the treatise here calls 閉尸) — are the same first three of the classical five embryonic stages used elsewhere on this site's Abhidharmakośa pages, kept as untranslated Sanskrit terms throughout this treatise as well. The tetralemma's point is a precise one: "eye" (as a sense field) and "the eye element" almost always coincide, but they are conceptually distinct enough that four genuinely different cases can be constructed — an arhat's very last moment of physical eye-function, present as an ordinary sense field but no longer generating any further seed for a future eye (hence no longer counted as "element" in the sense of an ongoing causal capacity); an unborn being who has the underlying seed-capacity (element) without yet having, or having already lost, the functioning organ itself; the ordinary case of both together; and the case of neither, once physical existence itself has ended for good, or one is born beyond form entirely. The manas/mental-faculty-element pair mirrors this exactly, with the attainment of cessation replacing the embryonic stages as manas's own temporary absence.

T1606 unpacks the four grounds where consciousness abides (identified elsewhere in the broader Yogācāra corpus as form, feeling, perception, and formations — the four non-consciousness aggregates, each a "ground" that consciousness settles into and takes root in) as the deeper structural reason the aggregates are counted in exactly this order, before restating the same point through ordinary causal sequence: seeing form causes a feeling, a felt experience gets construed into a recognizable image, a construed image drives one into some action, and action results in further discriminating consciousness of the outcome — each aggregate genuinely depending on the one before it, not merely listed in arbitrary sequence. The elements' order, by contrast, is explained through nothing more exotic than ordinary social custom: a guest is welcomed with sight, then speech, then touch (bathing, ointment), then smell (garlands), then taste (food), then further touch (bedding) — with the mental faculty's own reflective sorting-through of the whole visit coming last, only once every physical sense has already had its turn.

T1606 draws out one further layer behind the "heap" etymology: the sūtra's own list of eleven kinds of craving (concern for one's own body, hope, attachment, love of an inner self, love of an object, desire, love of concentration, painful craving for what is bad, joyful craving for what is good, distant craving, and near craving) is what actually grounds the treatise's finer distinctions — past, future, present, internal, external, and the rest — since it is precisely with reference to what each of these eleven kinds of craving can seize on that form (and each further aggregate in turn) gets sorted into a "past," "internal," "coarse," or "distant" instance to begin with. "Element," T1606 notes, unpacks its four senses onto the eighteen elements quite literally: the six faculty-elements and six object-elements hold the causal nature of what will produce a consciousness; the six consciousness-elements hold the resultant nature of what that causal pairing actually produces — cause and effect, quite exactly, distributed across the eighteen.

T1606 makes clear that the five similes and the five reasons are meant to be read together, matched one to one — each aggregate's simile chosen precisely because it best displays one of the five failures of a genuine self: foam looks solid from a distance but collapses the instant it is grasped, mirroring form's utter lack of any real self within it; a bubble is inherently unstable and short-lived, mirroring feeling's lack of any lasting purity; a mirage promises water that was never actually there, mirroring perception's thin, insubstantial "savor" — the sense that what it construes is genuinely nourishing or reliable; a banana tree, once peeled layer by layer, reveals no solid core or heartwood at its center at all, mirroring formations' lack of any solid, driving agent behind them; and an illusion appears vivid and convincing while having no genuine substance whatever behind its appearance, mirroring consciousness's own lack of any real, substantial knower standing behind the act of knowing. Taken together, the five similes are this chapter's own closing argument in miniature: everything painstakingly built across the last ten parts — every aggregate, element, and sense field, catalogued down to the last mental factor — amounts, in the end, to exactly this: form gathered like foam, feeling as brief as a bubble, perception as thin as a mirage, formations as hollow as a banana stalk, and consciousness as insubstantial as a conjured illusion.