The Twenty Kinds of Emptiness in the Mahāyāna Dharma

In Volume 51 of the Great Prajñāpāramitā Sūtra, the Buddha taught that the Great Vehicle has twenty kinds of emptiness, which bodhisattvas should cultivate and study. They are: inner emptiness, outer emptiness, inner-and-outer emptiness, emptiness of emptiness, great emptiness, emptiness of ultimate reality, emptiness of the conditioned, emptiness of the unconditioned, ultimate emptiness, emptiness of the boundless, emptiness of dispersion, emptiness of non-change, emptiness of intrinsic nature, emptiness of self-characteristics, emptiness of common characteristics, emptiness of all dharmas, emptiness of the unattainable, emptiness of non-nature, emptiness of self-nature, and emptiness of the self-nature of non-nature. The emptiness of worldly dharmas refers to non-existence, absence, non-being, and unattainability; the emptiness of the self-natured tathāgatagarbha refers to that kind of emptiness in which all marks of worldly dharmas are absent. It is different from worldly dharmas: its substance exists and is truly real; it is simply not cognized in the way worldly dharmas are cognized. If one tries to cognize the emptiness of the tathāgatagarbha by the means of cognizing worldly dharmas, one cannot cognize it correctly and will often misapprehend it. The meanings of the twenty kinds of emptiness are explained roughly as follows:

Inner emptiness refers to the emptiness of the inner dharmas: the eye, ear, nose, tongue, body, and mind. Outer emptiness refers to the emptiness of the outer dharmas: form, sound, smell, taste, touch, and mental objects. Inner-and-outer emptiness refers to the emptiness of both the inner and outer dharmas—the six inner sense bases and the six outer sense bases. Emptiness of emptiness means that all dharmas are entirely empty, and this emptiness itself is also empty. Great emptiness refers to the emptiness of the ten directions: east, west, south, north, the four intermediate directions, above, and below.

Emptiness of ultimate reality refers to the emptiness of nirvāṇa. Why is nirvāṇa empty? Because nirvāṇa is merely a state of tranquility manifested by the substance of the tathāgatagarbha. A state, of course, is not a real dharma—much less one that is merely revealed and displayed by the tathāgatagarbha. Do not confuse nirvāṇa with the substance of the tathāgatagarbha and fail to distinguish them; of the two, one is real and one is unreal.

Emptiness of the conditioned refers to the emptiness of the three realms: the desire realm, the form realm, and the formless realm. The three realms are produced through conditioning activity, and are therefore conditioned; dharmas that arise from non-existence into existence are naturally empty. Emptiness of the unconditioned refers to the emptiness of these phenomena of arising, abiding, changing, and ceasing; that is, the phenomena of arising, abiding, changing, and ceasing are empty, and the absence of arising, abiding, changing, and ceasing is something manifested, and is also empty. Existence and non-existence are merely provisionally established dharmas, mere verbal expression. Ultimate emptiness means that all dharmas are ultimately unattainable, and this unattainability is empty. Attainability and unattainability alike have no such thing; they are mere conceptual proliferation, and therefore empty.

Emptiness of the boundless means that in all dharmas there is no obtainable prior limit, middle limit, or later limit, and no obtainable limit of coming and going. The prior, middle, and later limits of the arising, development, and change of events are unattainable, and this unattainability is empty. That all dharmas have obtainable prior, middle, and later limits is empty; their unattainability is also empty; that all dharmas have limits of coming and going, development, and change is empty. For example, sentient beings' past, present, and future lives are empty, and the absence of limits of coming and going is also empty. All phenomena, properties, and states whatsoever are empty.

Emptiness of dispersion means that the phenomena of all dharmas dispersing, breaking apart, and being abandoned are empty; both gathering and dispersing are empty. Emptiness of non-change means that not altering, not changing, not dispersing, not breaking apart, and not abandoning—these phenomena are empty. Both change and non-change are empty; both are conceptual proliferation.

Emptiness of intrinsic nature means that the intrinsic nature of all dharmas is empty. Whether it is the conditioned nature of dharmas or the unconditioned nature of dharmas, it is not created by the Buddhas, bodhisattvas, śrāvakas, or pratyekabuddhas, nor is it created by ordinary beings. No one creates it; therefore it is empty.

Emptiness of self-characteristics means that the self-characteristics of all dharmas are empty. For example, the self-characteristic of the aggregate of form is material impediment, and this is empty; the self-characteristic of the aggregate of feeling is experiencing, and this is empty; the self-characteristic of the aggregate of perception is grasping images, and this is empty; the self-characteristic of the aggregate of formations is conditioning activity, and this is empty; the self-characteristic of the aggregate of consciousness is discernment, and this is empty. In this way, the self-characteristics of conditioned dharmas, as well as those of unconditioned dharmas, are all empty.

Emptiness of common characteristics means that the common characteristics of all dharmas are empty. For example, the common characteristic of defiled dharmas is suffering, and this is empty; the common characteristic of conditioned dharmas is impermanence, and this is empty; the common characteristic of all dharmas is emptiness and non-self, and this is empty. Seen in this way, the emptiness of the five aggregates and non-self realized by arhats is empty, and the twelve links of dependent origination realized by pratyekabuddhas is also empty. All dharmas have countless other common characteristics, and all of them are empty. Whether self-characteristics or common characteristics, all dharmas are empty.

 Emptiness of all dharmas means that the dharmas of the five aggregates, the twelve sense bases, and the eighteen elements—whether with form or without form, whether visible or invisible, whether with resistance or without resistance, whether defiled or undefiled, whether conditioned or unconditioned—are all empty.

Emptiness of the unattainable means that all dharmas are unattainable, and even this unattainability is empty and unattainable. All dharmas, including those of the past, present, and future, are unattainable. If one takes a stand on the past, there is no present or future to be attained; if one takes a stand on the future, there is no present or past to be attained; if one takes a stand on the present, there is no past or future to be attained. These unattainabilities are also empty.

 Emptiness of non-nature means that all dharmas have no properties or attributes whatsoever, and this very absence of nature is also empty. For example, water has no nature of water and no nature of non-water; it has no wetness or softness, no hardness or motility, and so on—no nature at all—and this very absence of nature is also empty. For example, the five aggregates have no nature of the five aggregates and no nature of non-five-aggregates; they have no nature at all, and this very absence of nature is also empty.

 Emptiness of self-nature means that the self-substance of dharmas is empty in nature, the capacity for self-mastery is empty in nature, and the capacity to combine and produce a self-substance is empty in nature. Emptiness of the self-nature of non-nature means that the lack of self-determination and self-mastery in dharmas is empty, and the fact that dharmas are subject to mastery is also empty; that is, the capacity of dharmas to combine is empty, and that which is combined is also empty.

The existence, non-existence, self-nature, and other-nature of dharmas are all empty. Emptiness of existence means that the nature of the existence of the five aggregates is empty. Emptiness of non-existence means that the unconditioned nature of dharmas is empty. Emptiness of self-nature means that all dharmas have no self-substance; this emptiness is not accomplished by wisdom, not accomplished by view, nor accomplished by any other dharma. Emptiness of other-nature means that whether a Buddha appears in the world or not, the abiding of dharma, the fixity of dharma, the nature of dharma, the realm of dharma, the nature of equality, the nature of freedom from arising, suchness (tathatā), non-falsity, non-changeability, and the limit of reality (bhūtakoṭi)—all are empty by reason of other-nature.

In short, whatever is spoken has no real meaning; whatever is known or viewed has no real meaning; whatever is indicated has no real meaning; whatever concepts there are have no real meaning; whatever deliberation and conditioning activity there is has no real meaning; whatever perception of dharmas there is has no real meaning. Empty it all the way to the bottom, until reaching that which can no longer be emptied—that is the emptiness that is not empty. Apart from it, everything is empty.