Chapter 3. Rūpa: A taxonomy of material phenomena¶

The task of this chapter. The previous chapter completed the inventory of consciousness. This chapter sets out its counterpart. The twenty-eight kinds of matter are not twenty-eight material constituents. They are twenty-eight qualities distinguishable when contemplating the body. They never occur singly. The actual smallest unit is the cluster. We can ask what produces each instance of a quality, and there are only four answers. This chapter first explains in modern language what questions the taxonomy answers. It then sets out the inventory, origins, modes of grouping, and lifespans, item by item. Apart from the overview, the chapter is largely a reference catalog to consult as needed and need not be read from beginning to end.

Overview: what the classification is saying. There are three points.

First, the twenty-eight kinds of matter classify qualities, not constituents. The characteristics of earth, water, fire, and air are hardness, flowing, warmth or cold, and supporting and pushing, respectively. All are predicates that can be directly felt in the body.¹ This analysis is neither a theory of particles nor a theory of elements. It does not ask what an object is made from. It asks only how many identifiable qualities can be distinguished in a body under observation.

Second, material dhammas do not arise singly. Wherever matter occurs, at least eight dhammas appear together: earth, water, fire, air, color, odor, taste, and nutritive essence. Tradition calls these the eight inseparable kinds of matter. Where the eye occurs, two more are added, making the eye decad. The inventory lists twenty-eight items, but what one actually encounters is always a cluster.²

Third, the four origins concern sources. An instance of the same quality can be produced by kamma, consciousness, temperature, or nutriment. This is an analysis of origins, unrelated to the analysis of constituents. It asks what brings forth this quality now appearing, not what the object consists of.

One need not look at a single table. These three points alone should make clear that the taxonomy deals with a body being contemplated, rather than a table of material composition.

First, what it is not. Chapter 3 of Essay 13 has already judged the characteristics of the four great elements to be experiential qualities. They are hardness, wetness, warmth, and motion. The way the discourses define the four elements can support this reading. The discourse on the simile of the elephant's footprint lists head hair, body hair, nails, teeth, coarse and fine skin, flesh, sinews, bones, and the like under the internal earth element. It lists brain matter, tears, sweat, mucus, saliva, pus, blood, fat, marrow, and the like under the internal water element.³ This is not a table of constituents. It is a list for identifying things, place by place, in one's own body.

Reading the twenty-eight kinds of matter in terms of particles, fields, or quantum theory is a textbook example of the preconceptions against which the guide to Part II warns. Earth does not mean a solid, nor water a liquid. Water's characteristics are flowing and cohesion, yet water is precisely what is excluded from tangible objects. Earth, fire, and air alone supply tangible objects, because only three types of quality can be touched: hardness and softness, cold and warmth, and pushing and supporting. Cohesion is inferred, not felt by touch.⁴ A theory of material composition would not exclude water from the tangible. A theory of what is found through contemplating the body would.

The twenty-eight kinds of matter are working units for contemplating the body. They have nothing to do with material composition. This statement supplies the general answer to two difficulties later in this chapter.

The four great essentials and twenty-four kinds of derived matter. The twenty-eight kinds of matter fall into two levels, four great essentials and twenty-four kinds of derived matter. "Derived" means dependent on the great essentials for existence, not assembled from them.

The four great essentials are earth, water, fire, and air. The twenty-four kinds of derived matter fall into nine groups.

There are five kinds of sensitive matter: eye, ear, nose, tongue, and body. Sensitive matter is not an organ. It is the sensitivity in an organ that can receive a particular kind of impingement. Eye-sensitivity has as its characteristic sensitive matter capable of receiving the impingement of a visible object. Its function is to direct the cognitive process toward visible objects. Its manifestation is to serve as the base for eye-consciousness. The other four follow the same pattern.⁵

There are four kinds of objective matter: color, sound, odor, and taste. Tangible objects receive no separate entry, since earth, fire, and air also perform that role. Hence only four kinds of objective matter are listed. With the three great essentials that supply touch added, they make up the five kinds of object commonly spoken of in the discourses.

There are two kinds of sex matter, the femininity faculty and the masculinity faculty. There is one heart-base, which serves as the base for the mind element and mind-consciousness element. One material life faculty maintains the kamma-produced matter in the same cluster for as long as it is due to persist. The one kind of nutritive matter is the nourishment in food, or nutritive essence, which will recur throughout the discussion below.

One kind of delimiting matter marks the boundaries between material clusters. The two kinds of intimating matter are bodily intimation and verbal intimation, the material aspects of bodily action and speech. The three kinds of mutable matter are material lightness, malleability, and wieldiness. The four material characteristics are production, continuity, aging, and impermanence.

This chapter does not reproduce the characteristic, function, manifestation, and proximate cause of every kind of matter. Readers who need to compare them item by item should consult the Charts for the Compendium of Abhidhamma directly.¹

Concretely produced and nonconcretely produced matter. The treatise draws a further boundary within the twenty-eight kinds of matter. The first eighteen are concretely produced, and the last ten are nonconcretely produced. Concretely produced matter comprises the four great essentials, five kinds of sensitive matter, four kinds of objective matter, two kinds of sex matter, the heart-base, the life faculty, and nutritive essence, eighteen in all. Nonconcretely produced matter comprises one kind of delimiting matter, two kinds of intimating matter, three kinds of mutable matter, and four material characteristics, ten in all.²

The treatise states clearly where this boundary falls. Concretely produced matter possesses own-nature and is therefore suitable as an object of insight meditation. Nonconcretely produced matter is not directly produced by the four causes of material dhammas. It consists only of qualities of concretely produced matter.⁴ Concretely produced matter has a string of synonymous names: matter possessing own-nature, matter possessing its own characteristic, real matter, matter as such, and matter to be comprehended by insight knowledge. The last name is the most revealing. In practical terms, the distinction between concretely produced and nonconcretely produced matter comes down to whether contemplation can take it separately as an object.

This boundary is worth remembering, because the questions raised at the end of this chapter all concern the portion set apart on its other side.

The two levels and two divisions together yield the following diagram. The four great essentials occupy the top row, with the twenty-four kinds of derived matter below in ten groups. The line at the left separates eighteen kinds of concretely produced matter from ten kinds of nonconcretely produced matter. The boundary falls after nutritive essence.

The four origins: what produces this instance of a quality? There are four causes: kamma, consciousness, temperature, and nutriment.

Later sections will discuss what each of these four terms means. Here, an example of each will keep the counts below from being merely four columns of numbers.

Kamma means past volition, restricted to twenty-five kinds: the mental factor of volition in twelve unwholesome cittas, eight great wholesome cittas, and five form-sphere wholesome cittas.⁴ Chapter 2 counted twenty-nine mundane cittas that produce kamma. The four missing here are the wholesome cittas of the immaterial sphere. The sphere in which they bring about rebirth contains no matter to begin with, so naturally they cannot produce matter. Kamma produces the features this body is born with. These are the five kinds of sensitive matter (eye, ear, nose, tongue, and body), the male and female sex faculties, the heart-base that supports the mind element and mind-consciousness element, and the life faculty that maintains their existence. Which kamma produces which kind of matter? The treatises answer only in the column for proximate cause. The proximate cause of eye-sensitivity is the four great essentials produced by kamma conditioned by the desire to see. That of ear-sensitivity is the four great essentials produced by kamma conditioned by the desire to hear. Nose, tongue, and body follow the same pattern.⁵ Kamma therefore does not allot an instance of matter to each individual deed. At the moment of rebirth-linking it establishes the whole set, then produces it anew at every moment thereafter. However much one now wishes to see clearly, that wish cannot produce a single instance of eye-sensitivity.

Consciousness means present consciousness. Seventy-five of the eighty-nine cittas can produce matter. The exclusions are the two sets of five sense-consciousnesses and the four resultant cittas of the immaterial sphere.⁴ What consciousness produces is the bodily appearance of intention. In raising a hand, nodding, or walking, the feature through which another can discern the intention is bodily intimation. The shaping movements of mouth and tongue in speech are verbal intimation, and the speech sound that accompanies them likewise comes from consciousness.¹ The three kinds of mutable matter also appear in the consciousness-produced column. When one's state of mind changes, the body's heaviness or lightness, softness or stiffness changes with it. One function assigned to rapture in the table of mental factors is precisely to spread excellent consciousness-produced matter throughout the body.¹

Temperature means the fire element in a material cluster. Upon reaching its phase of presence, it produces a new generation of material clusters. This holds both inside and outside the body.⁴ Everything nonliving outside the body has this one source alone, including rocks, rivers, plants, and the sounds of thunder and wind.

Nutriment means the nutritive essence ingested with food. It spreads through digestion and likewise produces a new generation of octads during its phase of presence.⁴ On the material side, this is what it means for a meal to sustain the body.

Eight dhammas are common to all four causes: earth, water, fire, air, color, odor, taste, and nutritive essence. These are the eight inseparable kinds of matter mentioned above. All eight are present in a material cluster produced by any of the causes.

If we count by affiliation to the four origins and include derivative matter, each column contains the following items in addition to the inseparable eight. The kamma-produced column adds ten: five kinds of sensitive matter, two kinds of sex matter, the heart-base, the life faculty, and delimiting matter. The consciousness-produced column adds seven: sound, delimiting matter, bodily intimation, verbal intimation, and three kinds of mutable matter. The temperature-produced column adds five: sound, delimiting matter, and three kinds of mutable matter. The nutriment-produced column adds four: delimiting matter and three kinds of mutable matter. Eight plus ten makes eighteen, eight plus seven makes fifteen, eight plus five makes thirteen, and eight plus four makes twelve.¹

Expanded item by item, the coverage forms the following matrix. The rows are the twenty-eight kinds of matter, and the columns are the four causes. A filled mark means that this cause can produce this kind of matter.

Several points in this table deserve attention.

First, the five kinds of sensitive matter, two kinds of sex matter, heart-base, and life faculty are produced only by kamma. They have no second source. All that gives a body its faculties and its bases for consciousness falls in the kamma-produced column. The other three causes can produce only what the body shares with nonsentient things.

Second, the two kinds of intimating matter appear only in the consciousness-produced column. Nothing but present consciousness can bring forth the material appearance of action and speech.

Third, the four material characteristics appear in none of the columns. The section on lifespan below explains why. Material characteristics refer to the arising, presence, and dissolution of what is produced. They are not themselves separately produced.

Fourth, delimiting matter appears in all four columns, but the subject here is affiliation to an origin, not composition within a cluster. There are gaps between the material clusters produced by all four causes, so delimiting matter can be assigned derivatively to all four. The treatise then expressly states that it marks the boundaries of material clusters but is not an item inside any cluster.²

Fifth, sound appears only in the consciousness-produced and temperature-produced columns. Speech sound comes from consciousness, and other sounds come from temperature. Neither kamma nor nutriment can produce sound.

Their starting points also differ. Kamma-produced matter begins to arise at the arising phase of rebirth-linking consciousness. It continues uninterrupted through the arising, presence, and dissolution phases of every subsequent mind-moment. Consciousness-produced matter begins only with the first bhavaṅga after rebirth-linking, and arises only in the arising phase of each citta. No consciousness-produced matter arises during the moment of rebirth-linking consciousness. The two sets of five sense-consciousnesses excluded earlier are excluded for the same reason. They lack the power to produce material dhammas.⁴ There is a boundary at the other end as well. From the presence phase of the seventeenth citta before death consciousness onward, kamma-produced matter ceases to arise.⁴ Seventeen appears here for the first time. The next section explains it.

Material clusters: matter does not arise singly. We must first distinguish two levels of sources. The text of the Abhidhammattha Saṅgaha lists twenty-one clusters: nine produced by kamma, six by consciousness, four by temperature, and two by nutriment. Pa-Auk meditation instruction adds two to the six consciousness-produced clusters: the consciousness-produced sound nonad of in-and-out breathing and the consciousness-produced sound-and-lightness dodecad of in-and-out breathing. This makes twenty-three: nine produced by kamma, eight by consciousness, four by temperature, and two by nutriment.^{2 6} The itemized account and diagram below use the latter twenty-three, to align with the meditation teaching tables on which they draw. This is a later teaching extension, not the number originally given in the treatise.

All nine kamma-produced clusters contain the inseparable eight and the life faculty, with one further item added in each case. The eye decad adds eye-sensitivity, and the ear, nose, tongue, and body decads follow the same pattern. The femininity decad adds the femininity faculty, the masculinity decad adds the masculinity faculty, and the heart-base decad adds the heart-base. The ninth is the life nonad, which adds nothing. The eight plus the life faculty make nine.

The eight consciousness-produced clusters are: the pure octad; the bodily-intimation nonad; the verbal-intimation decad, adding sound and verbal intimation; the lightness undecad, adding the three kinds of mutable matter; the bodily-intimation-and-lightness dodecad; the verbal-intimation-sound-and-lightness tridecad; the consciousness-produced sound nonad of in-and-out breathing; and the consciousness-produced sound-and-lightness dodecad of in-and-out breathing.

The four temperature-produced clusters are the pure octad, the sound nonad, the lightness undecad, and the sound-and-lightness dodecad.

The two nutriment-produced clusters are the pure octad and the lightness undecad.¹

The twenty-three clusters in the Pa-Auk teaching system appear side by side below. In each cluster, the inner ring contains the fixed inseparable eight, and the outer ring contains its additions.

The composition of the eye decad best illustrates the second point of the overview. Where the eye is, hardness, flowing, temperature, and pushing and supporting are all present at once. Color, odor, taste, and nourishment are present at the same time, together with a life force that maintains it and sensitivity that can receive the impingement of a visible object. The inseparable eight plus the life faculty and eye-sensitivity make exactly ten items. Delimiting matter manifests as the gap between this cluster and neighboring material clusters. It is not counted among the ten. Contemplation of the body can distinguish the items within the cluster, but none can appear alone. The inventory has twenty-eight entries, yet contemplation encounters only clusters.

Like the previous chapter's inventory, this one is for reference during contemplation of the body. There is no need to memorize it.

The lifespan of matter: seventeen mind-moments. A mind-moment is further divided into three submoments: arising, presence, and dissolution. The treatise then states that the lifespan of material dhammas is seventeen moments of consciousness.⁷ Mental and material dhammas have arising and dissolution phases of equal length, but the presence phase of a material dhamma equals forty-nine mental submoments. Counted in submoments, one plus forty-nine plus one makes fifty-one.^{4 8}

What matters about this number is not its size but the fact that it is a number. Assigning a lifespan to an instance of a quality acknowledges that it arises and ceases, with a beginning and an end. Whatever has a time limit is a process. This book takes this to be one of the easiest points to miss in the taxonomy of twenty-eight kinds of matter. Its twenty-eight entries look like twenty-eight things, yet each is explicitly assigned a time limit. Within this analysis, the continued existence of an object can only be explained as the arising of material dhammas of the same kind, generation after generation. There is no unmoving bearer between them. Each entry is best read as an event with a beginning and an end. This point will face a challenge in each of the next two sections.

Not all matter persists this long. There are two groups of exceptions, for different reasons.

The two kinds of intimating matter persist for only one moment of consciousness.⁸ Bodily and verbal intimation are the material appearances of action and speech. They come from consciousness, and a given instance of intimation ends when the episode that produces it ends. A gesture can be seen as a continuous action because a series of cittas arises in succession, each bringing forth its own instance of intimating matter.

The four material characteristics go further. They are the process itself. The treatise calls material production, continuity, aging, and impermanence "material characteristics." Among them, the arising of matter is spoken of under the two names "production" and "continuity."⁷ Nārada explains plainly that the first moment of consciousness resembles production, the last resembles impermanence, and the fifteen in between resemble aging.⁸ Material characteristics refer to the beginning, middle, and end of this seventeen-mind-moment process, not to four additional things. To give them a further lifespan would be to give a lifespan to a lifespan.

The calculation can therefore be made as follows. Remove the two kinds of intimating matter and four material characteristics from the twenty-eight, and the remaining twenty-two persist for the full seventeen mind-moments. Counting the included items also yields twenty-two, comprising eighteen kinds of concretely produced matter, delimiting matter, and three kinds of mutable matter. Nārada's notes to his English translation give twenty-three here.⁸ The discrepancy comes from the inventory used. He excludes five items: the two kinds of intimating matter, arising, aging, and impermanence. Production and continuity have already been combined into the single entry "arising," so this is a count based on twenty-seven kinds of matter. Twenty-seven minus five is twenty-two. This chapter uses the twenty-eight-item inventory, with production and continuity occupying one entry each. Six items must therefore be excluded, and twenty-eight minus six is again twenty-two. The number twenty-three results from subtracting the exclusions of the twenty-seven-item inventory from the total of twenty-eight. Two inventories have been mixed in one calculation. Follow either route through consistently and the result is twenty-two. This book uses twenty-two.

There is another distinction we should not blur. The fifteen moments of consciousness in the middle and the earlier formula "one plus forty-nine plus one" do not use units at the same level. The former counts moments of consciousness, and the latter counts submoments. The two counts cannot be lined up for a direct conversion.

Lifespan, material characteristics, and these two groups of exceptions together form the following strip.

Does a rock exist for only seventeen mind-moments? This is the question most likely to arise on reading the section on lifespan. Do the rocks, mountains, and houses outside also live for only seventeen mind-moments?

The first level of the answer returns to the third point of the overview and the general answer stated above. The twenty-eight kinds of matter are working units for contemplating the body. This inventory is designed for contemplation of the body from beginning to end. The scriptural evidence for the four great elements lists head hair, body hair, nails, and teeth, as well as tears, sweat, mucus, and saliva. Sensitive matter is defined as a base for consciousness. Sex matter, the heart-base, and the life faculty make sense only in relation to sentient beings. Taking this inventory out to measure a rock means using a tool where it was never meant to apply. In this book's judgment, asking how many mind-moments a rock can live is the same kind of misplacement as asking how many kilograms of ore a medical examination report can measure.

The second level of the answer comes from the treatise itself, which gives it plainly. Only two kinds of material cluster can be found externally, both temperature-produced: the pure octad and the sound nonad. All other material clusters occur only internally.⁹ The treatise never applies the whole twenty-eight-item inventory to external things. Only eight or nine dhammas are assigned to the interiors of their material clusters. Sensitive matter, sex faculties, the heart-base, the life faculty, and intimating matter do not appear in a rock's material clusters. Delimiting matter merely describes the gaps between external material clusters. It does not become a constituent inside a pure octad or sound nonad. Material characteristics are likewise not constituents of a material cluster.

How, then, do these eight dhammas sustain a rock? They do so through one generation after another. When a material cluster reaches its phase of presence, its fire element can, as circumstances allow, produce a new generation of temperature-produced material clusters internally or externally. The fire element of the new generation can then produce the next.⁴ The Visuddhimagga states more directly that temperature-produced matter continues for a long time among things not clung to and maintains itself.¹⁰ Mahinda's lectures put the point most plainly. All nonliving material phenomena are merely temperature-produced matter. The material world, including the body, can exist for a long period precisely because these material clusters keep arising and ceasing, generation after generation.¹¹

So the rock really is continually new. Each particular material cluster persists for only seventeen mind-moments. A rock that appears unchanged for thousands of years is a relay of material clusters spanning thousands of years. What continues is the form and causal chain, not any one instance of matter. The number seventeen has not been violated. It has always governed a single material cluster, not an object.

If nutritive essence can support many generations, does it live longer? The previous section's answer immediately raises the next question. The treatise explicitly says that when nutritive essence in a nutriment-produced material cluster reaches its phase of presence, it can produce a new generation of pure octads. That generation's nutritive essence can produce the next, continuing for ten to twelve generations. It also says that food eaten in one day can maintain the body for as long as seven days, while the essence of celestial food can do so for one or two months.^{4 10} Seven days far exceeds seventeen mind-moments. Does nutritive essence therefore live longer than other kinds of matter?

No. Two things must be distinguished here: how long an instance of a material dhamma persists, and how long a causal chain it can set in motion.

Nutritive essence also persists for only seventeen mind-moments. Ten to twelve generations refers to what it sets in motion before it ceases. The first generation's nutritive essence produces the second during its phase of presence, then ceases as usual. The second generation's nutritive essence produces the third during its phase of presence, then ceases as usual. Twelve generations are twelve instances of nutritive essence arising and ceasing successively. No single instance thereby lives twelve times as long. Saying that one day's food sustains the body for seven days means that this chain can continue for seven days. Each link in it still arises and then ceases.¹⁰

In this book's view, the confusion here follows a general pattern. It mistakes the duration of causation for the duration of existence. A match lights a pile of wood, and the wood burns for three days. No one would say that the match burned for three days. This is precisely the step that Abhidhamma guards against throughout its treatment of matter. It fixes the lifespan of each instance of matter at seventeen mind-moments, then explains every enduring phenomenon in terms of continuity, leaving no place where a lifespan can quietly be extended. The rock in the previous section and nutritive essence in this one prompt different questions, but the answer is the same.

Accounts differ on the number of generations, so their sources must be distinguished. Section 703 of the Visuddhimagga and the Compendium give ten to twelve generations. The Pa-Auk lectures follow them, identifying the Great Subcommentary to the Visuddhimagga as their source. Mahinda's lectures give four or five generations when discussing nutriment-produced matter. They separately assign counts to temperature-produced matter according to the source of its fire element. These are ten to twelve generations for nutriment-produced fire, four or five for kamma-produced fire, and two or three for consciousness-produced fire.^{10 12 11} Treatises and lectures do not stand at the same level. The latter two offer experiential explanations in meditation instruction. This book's main text uses only the treatises' numbers. The lecture counts are included here for reference.

A terminological clarification may help. Nutritive matter among the twenty-eight kinds of matter is ojā in Pali, or physical food, the first of the four nutriments. The other three are contact as nutriment, mental volition as nutriment, and consciousness as nutriment. All three are mental dhammas and fall outside this inventory of material dhammas.⁴ Throughout this section, "nutritive essence" means the material item.

Dependence, support, and generation. Each preceding section has addressed one part of the account. The four great essentials and derived matter constitute a structural level. The four origins are four sources, material clusters are the smallest units, and seventeen mind-moments is the time limit. Taken together, these sections show that there are only three kinds of relation among the twenty-eight kinds of matter. Only once these three are clear is the taxonomy's framework complete.

The first is dependence. The twenty-four kinds of derived matter depend on the four great essentials. Without them, not one can stand. Yet derived matter is not assembled from the great essentials. Sensitive matter is not some arrangement of the four. It has its own characteristic and function.⁵ The four great essentials likewise depend on one another. Earth, water, fire, and air within a material cluster arise and cease together. Remove any one, and the other three cannot be established either. Dependence concerns simultaneity. The two items are together in one material cluster, with no earlier and later to distinguish.

The second is generation, or the four origins. Four causes produce matter: kamma, consciousness, temperature, and nutriment. Two of these causes are mental dhammas and two are material dhammas. Kamma is past volition, and consciousness is present consciousness. Both fall on the mental side. Temperature is the fire element in a material cluster, and nutriment is its nutritive essence. Although these two fall on the material side, they are themselves produced by other causes. The material side is therefore not closed. It has two openings to the mental side, one in the past and one in the present.

Of these, the route of consciousness-produced matter best illustrates the third point of the overview. A citta arises and simultaneously brings forth an instance of matter. That citta ceases, and this instance of matter has no fresh continuation. Bodily and verbal intimation arise from consciousness alone.¹ In this system, speech and action are matter produced on the spot by mental dhammas. No ready-made thing moves within them.

The third is support. It differs from generation in that it produces no new matter, serving only to maintain it. The life faculty maintains co-arising kamma-produced matter, and only that column. Matter in the other three columns is not maintained by it.¹ Nutritive essence makes no distinction between columns. The nutritive essence in a material cluster supports the kinds of matter in that same cluster. Upon reaching its phase of presence, it separately produces a new generation of pure octads, one generation after another. The treatises give ten to twelve generations.¹⁰ Support and generation are two different things. Nutritive essence supports the present cluster and generates the next. Neither requires it to live beyond seventeen mind-moments.

The route through the fire element follows the same principle and extends further. During its phase of presence, the fire element in a material cluster produces a new generation of temperature-produced clusters. The new clusters also contain a fire element, which can produce the next generation. This is precisely how the rock in the previous section remains in the world. Matter of the same kind arises generation after generation, each still persisting for only seventeen mind-moments.¹¹

Finally, one line runs back in the other direction. Where mentality and materiality are both present, consciousness and mental factors cannot arise alone. The treatises call this five-aggregate existence. The five sense-consciousnesses depend on the five kinds of sensitive matter, and the remaining cittas depend on the heart-base.^{5 1} Mental dhammas produce matter, and matter in turn serves as a base for mental dhammas. Each side supports the other, and neither is the other's foundation. The cognitive processes discussed in Chapter 4 are this correspondence unfolding in time.

The three relations combine in one diagram.

A comparison with Sarvāstivāda. Sarvāstivāda has eleven material dharmas: five faculties, five objects, and unmanifest matter.¹³ Theravāda has twenty-eight. The difference lies in the principles for positing dhammas, not in the fineness of observation.

Theravāda divides among several items what Sarvāstivāda assigns to one, and also makes dhammas of things Sarvāstivāda does not posit as dharmas. Sarvāstivāda posits none of the three kinds of mutable matter, four material characteristics, or one kind of delimiting matter as dharmas. Theravāda, in turn, does not posit Sarvāstivāda's unmanifest matter as a dhamma.

Unmanifest matter warrants the closest attention. Sarvāstivāda seeks to explain where the substance of the precepts is when a person who has undertaken them is asleep. Its answer is to posit a dharma, a kind of matter that does not appear externally. It arises when the precepts are undertaken and continues until they are relinquished or life ends. Theravāda takes a different route. It has no entity bearing the substance of the precepts. Their persistence is sustained by the manifestation of abstinence factors whenever the relevant conditions are encountered, and by the conditioning relations thereby left behind. This book takes this to be a choice we can see clearly. Sarvāstivāda prefers to posit an additional entity to sustain persistence. Theravāda prefers to let conditions do so. The succession of generations that has recurred throughout this chapter is the general solution this Theravāda approach supplies for material dhammas.

The two complete inventories can also be viewed together. Theravāda has eighty-two ultimate dhammas: one consciousness, fifty-two mental factors, twenty-eight kinds of matter, and one Nibbāna. Sarvāstivāda has seventy-five dharmas: eleven kinds of matter, one consciousness, forty-six mental factors, fourteen conditioned factors dissociated from mind, and three unconditioned dharmas.^{13 2} More than half the discrepancy falls in the columns for matter and for conditioned factors dissociated from mind. These are precisely where the two sides are respectively willing to posit dhammas for formal features. The next essay will directly address what Sarvāstivāda posits. This chapter offers only a comparison.

Which items are found through contemplation? Part of the inventory of derived matter results from observation. Another part is added to complete the taxonomy itself. The boundary drawn earlier has already defined the scope of discussion. The eighteen kinds of concretely produced matter are uncontroversial. All the items requiring consideration lie among the ten kinds of nonconcretely produced matter, and three groups deserve particular scrutiny.

The first group consists of the two kinds of intimating matter. Bodily and verbal intimation are posited as material dhammas, yet their characteristics are to indicate one's intention through movement and to express one's intention through speech.¹ Indicating and expressing are relational predicates. They require someone who can understand them to be present. An instance of a material dhamma includes another observer in its characteristic. This is the only such case among the twenty-eight kinds of matter.

The next item is delimiting matter. Its characteristic is to delimit material clusters, and its manifestation is the openings between them. A boundary is a relation between clusters. Making a relation into an item of matter is the most formal move in this inventory. It is assigned derivatively to all four causes because boundaries must be drawn between clusters produced by all four, not because each cluster contains an item of delimiting matter within itself.

The last group consists of the four material characteristics. As already noted, these are the beginning, middle, and end of those seventeen mind-moments. A problem arises once the divisions of a process are made into four entries in an inventory and we ask how long those entries persist. The treatise deals with this by excluding material characteristics from the seventeen-mind-moment lifespan. In this book's view, that step resolves a difficulty of notation, while leaving the problem itself where it was.

The three groups share one feature. The points requiring consideration all fall on the side of relations and form, not on that of qualities. The first eighteen kinds of matter can be directly identified in contemplating the body. More than half of the last ten perform formal duties that allow this notation to constitute a system of its own. This chapter offers only the criterion. Can an item be taken separately as an object of insight meditation? Chapter 7 will draw the conclusion.

One further comparison will be recorded here without an answer. The mental side posits two levels, consciousness and mental factors. A mental factor must arise and cease with consciousness, share its object, and share its base. Only when all four conditions are met does it count as associated. The material side is arranged as a flat table of twenty-eight parallel items, without a corresponding second level. Yet the relation of the three kinds of mutable matter, two kinds of intimating matter, and four material characteristics to concretely produced matter looks just like that of mental factors to consciousness. None of these three groups is an independent quality. All manifest only in concretely produced matter, and none can be taken separately as an object. The format of association was already available. Why does the material side not use it? This chapter leaves the question for Chapter 7.

On to Chapter 4. Matter persists for seventeen mind-moments, and seventeen mind-moments is precisely the length of a complete five-door cognitive process. The previous chapter inventoried consciousness, and this chapter inventories matter. The two inventories join at this number. The next chapter discusses cognitive processes, and the number will reappear from the other end.

Measuring material dhammas in mind-moments raises a further question. Is it circular to measure matter in mental units, then use matter's duration to explain the persistence of an object? This concerns the principles for positing dhammas. This chapter leaves it for Chapter 7.

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