Emptiness: Empty of what?

Why a familiar English word can become an obstacle to understanding Buddhism.

I have spent much of my life reading mathematics, science, philosophy, and spiritual literature. Yet when I began studying Buddhism seriously, some of the most ordinary-looking words became surprisingly difficult: emptiness, no-self, suffering, aimlessness, signlessness.

I wondered why ideas that eventually seemed so close to direct experience were initially hidden behind words that suggested something quite different.

This is the first chapter of an unfinished investigation into those words. I am not proposing new Buddhist doctrines. I am trying to notice what a modern reader thinks a word means, examine what the Buddhist texts actually say, and then ask whether the teaching can be observed in ordinary life.

The first misunderstanding: nothing is there

When I have asked people what emptiness means, an answer I have heard is simple: there is nothing. This is understandable. We see an empty room, an empty shelf, an empty cup. We imagine a space deprived of its contents.

But take the empty cup seriously for a moment.

Empty of what?

Usually we mean that it has no water, tea, or coffee in it. Yet it may still contain air. It has a shape, material, weight, a temperature, a history of manufacture, and a relationship to the person who calls it a cup. Even if I remove all the air, I have not thereby removed the cup itself.

So an ordinary statement—“the cup is empty”—already depends on an unspoken qualification. Empty of something is not the same as empty of everything.

That observation is a useful doorway. But it is not yet the whole Buddhist teaching of emptiness.

What the mathematician means

Mathematics is more precise in a different way. The empty set, written ∅, is the unique set with no elements:

|∅| = 0.

This is a rigorous mathematical definition, not a vague assertion that nothing exists anywhere. The set containing zero, {0}, is not empty; it has exactly one member.

There is no problem with mathematics here. A set is an abstract object, and we may use sets to model aspects of physical situations. For instance, if we define a set of water droplets in a completely dry cup, that set may be empty. But this says nothing about whether the cup contains air, has a handle, or was made in a factory. We chose the question first, and the mathematics answered that question precisely.

The empty set is not a rival account of Buddhist emptiness. It answers a different kind of question. Mathematics can describe the world extraordinarily well, but a formal description of selected objects or properties should not be confused with the entirety of lived reality.

A striking example from the early discourses

In the Cūḷasuññata Sutta (MN 121), the Buddha describes a dwelling as empty of elephants, cattle, gold, and crowds, while acknowledging what is still present. The discourse repeatedly insists on discerning both what is absent and what remains.

That is an important discipline of attention: do not call something nothing merely because the thing you expected to find is absent.

In another discourse, the Suñña Sutta (SN 35.85), the Buddha explains that the experienced world is empty of a self and of what belongs to a self. He applies this to seeing, hearing, sensing, thinking, contact, and feeling.

These passages do not define emptiness as a mathematical empty set. Nor do they say that sights, sounds, sensations, and feelings simply fail to occur. They direct investigation toward what, in experience, is absent—and particularly toward the self we assume we will find there.

Nāgārjuna asks a deeper question

In the Madhyamaka tradition, Nāgārjuna develops the discussion further. Things are described as empty of svabhāva—a fixed, independent nature or inherent existence. His Mūlamadhyamakakārikā (24.18) connects emptiness with dependent arising and dependent designation.

Consider the cup again. It is made from materials, through processes, under conditions; it functions as a cup in relation to bodies, liquids, language, and use. It exists and can hold tea. But can I identify within it a completely independent, unchanging cup-essence that makes it what it is without dependence on anything else?

The point is not that the cup vanishes when examined, or that it is merely imaginary. The point is to question whether it exists in the self-contained way I may unconsciously suppose.

The early-discourse presentation and Nāgārjuna's Madhyamaka analysis are connected but not identical. I want this series to preserve those differences rather than compress centuries of Buddhist thought into one simplified slogan.

Is Buddhist Emptiness the Opposite of Upaniṣadic Fullness?

In the traditional invocation associated with the Īśā Upaniṣad, we encounter the expression pūrṇam adaḥ, pūrṇam idaṃ — “That is full; this is full.”

At first glance, fullness and emptiness appear to be opposites. In mathematics, the empty set and the universal set are complements relative to a defined universe.

But is that the meaning of emptiness in Buddhism?

The Buddha did not describe phenomena as mathematically empty sets. In SN 35.85, he explains that the world is empty of self and what belongs to self. In Nāgārjuna's Madhyamaka, phenomena are understood as empty of independent intrinsic existence.

This is empty. That is empty. But it does not follow that everything is one.

Similarly, Buddhist emptiness cannot be declared the opposite of Upaniṣadic fullness merely by comparing the English words.

The Buddha also discussed “the all” (sabba) in SN 35.23, but this should not be confused with the Upaniṣadic concept of pūrṇa or Brahman.

Whether these philosophical understandings are compatible is a separate investigation. The Buddhist explanation of emptiness alone does not establish or refute every metaphysical claim about an ultimate whole.

The lesson is simple: before comparing two teachings, we must first understand what their words mean within their own contexts.

When another tradition explains Buddhism through its own philosophy

The difficulty of translation is not limited to English words. Even highly respected spiritual teachers can describe Buddhism through the concepts of their own traditions. A revealing example is Swami Vivekananda, whose admiration for the Buddha was sincere and whose work encouraged religious dialogue, education, and compassionate service.

In his address Buddhism, the Fulfilment of Hinduism at the Parliament of the World's Religions in Chicago on 26 September 1893, Vivekananda said:

“Shâkya Muni came to preach nothing new.”

He described the Buddha's message as:

“the fulfilment, the logical conclusion, the logical development of the religion of the Hindus.”

These are Vivekananda's actual words, not my reconstruction. His text is available from Belur Math, the Ramakrishna Order's headquarters. He also credited the Buddha with compassion and a wide dissemination of spiritual teachings. The intention of this comparison is not to dismiss that respect. It is to ask whether fulfilment of Vedānta is an adequate account of what early Buddhist texts teach.

The distinction becomes clearer when we compare specific claims rather than religious labels:

Question	Vivekananda's Vedānta-oriented outlook	Early Buddhist texts
What is the self?	An ultimate Ātman, ultimately one with Brahman, is affirmed. In his Discourses on Jnana-Yoga, Vivekananda writes: “There is but one Self in the universe.”	In SN 22.59, the Buddha directs the practitioner not to regard form, feeling, perception, formations, or consciousness as self, or as belonging to a self. The text does not conclude that an eternal Brahman lies behind these aggregates.
What is liberation?	In Advaita, liberation centrally involves recognizing the true Self as Brahman, beyond apparent separateness.	Early Buddhist teachings emphasize the ending of ignorance, craving, and clinging through the path. Nibbāna is not presented as discovering one's identity with Brahman.
Why trust a teaching?	Vivekananda accepts the Vedas as an authoritative source of spiritual revelation while encouraging realization rather than mere belief.	In MN 95, the Buddha questions whether inherited oral tradition, faith, and reasoning alone warrant declaring a teaching uniquely true. Vedic lineage does not settle the investigation.
What does 'empty' deny?	Nondual Vedānta distinguishes changing appearances from an ultimate reality, Brahman.	In SN 35.85, the experienced world is described as empty of self and what belongs to self. In Nāgārjuna's later Madhyamaka, things are empty of independent intrinsic nature. This is not another name for Brahman.

This comparison is not a judgment on all Hindu philosophies, which differ substantially, or on all Buddhist schools, which also interpret self, emptiness, and ultimate truth in different ways. It compares a specific Vedānta-oriented reading with identifiable Buddhist sources. Nor should we project the fully developed system of Śaṅkara's Advaita, formulated many centuries later, back into the lifetime of the Buddha.

The Buddha lived within the religious and intellectual world of ancient India and participated in the wider śramaṇa movements. Buddhist and Brahmanical thinkers shared questions about karma, rebirth, renunciation, and liberation—and also disputed important answers. In particular, the earliest Buddhist discourses do not accept the Vedas as decisive authority, and their treatment of self cannot simply be replaced by the Advaitic discovery of an eternal Self. Calling the Buddha a Hindu in today's religious sense can obscure that historical setting; it is not a sufficiently precise description of his doctrine.

What, then, was Vivekananda mistaken about? I would phrase the issue carefully: his claim that the Buddha preached nothing new blurs philosophical differences that the early Buddhist texts make explicit. I cannot establish what he privately understood, and I would not attribute bad faith to him. His public interpretation sought a spiritual synthesis; a comparison with the original Buddhist discourses shows where that synthesis stops being an accurate description of the texts.

Appreciating a teacher is one thing. Treating every spiritual tradition as saying the same thing is another. Respect is compatible with examining the precise claims, especially when a single word such as self, emptiness, or liberation may refer to different things.

Why the translation matters

To an English reader, empty often means nothing inside. In Buddhist contexts, the crucial question is frequently empty of what? The answer changes depending on the teaching and tradition: empty of self and what belongs to self; empty of an independent intrinsic nature; or, in a meditation instruction, empty of the disturbances one has set aside.

It is tempting to say that Buddhism simply “redefines” emptiness. That would be too easy. More precisely, English emptiness translates technical Buddhist terms whose meanings are established by particular teachings and contexts. The English word brings everyday expectations that may not fit those uses.

The difficulty is therefore not evidence that ordinary language, mathematics, or Buddhism is mistaken. The difficulty is that one familiar word is being asked to do several different jobs.

Returning to direct observation

I can understand all this intellectually and still miss what it invites me to examine.

So I can begin with an ordinary cup in my hand. I see its color and shape; I feel its weight and temperature; thoughts arise about its name, purpose, value, and ownership. If I attend carefully, I do not find a permanent, independent controller standing apart from seeing, touching, recognizing, and thinking. These experiences appear in relation to changing conditions.

This brief observation does not prove Nāgārjuna's entire philosophy. Nor does it entitle me to announce that I have realized emptiness. It gives me something more modest and useful: a place to investigate where assumptions are being added to experience.

Perhaps that is where modern explanations of Buddhist terminology should begin—not by making ancient teachings sound mysterious, but by identifying the particular misunderstanding each word invites.

The next time I hear “everything is empty,” I want to ask, carefully and without rushing: empty of what?

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Sources and further reading

• Vivekananda, Buddhism, the Fulfilment of Hinduism (1893), Belur Math — his direct words, including the claim that the Buddha taught nothing new.
• Vivekananda, Discourses on Jnana-Yoga, Complete Works, Vol. 8 — his affirmation of the ultimate Self.
• Anattalakkhaṇa Sutta (SN 22.59), SuttaCentral — the early Buddhist argument regarding the five aggregates and not-self.
• Caṅkī Sutta (MN 95), SuttaCentral — a critical examination of claims based on Vedic oral lineage.
• Stanford Encyclopedia of Philosophy, “Buddha” and “Śaṅkara” — historical background and differences between early Buddhism and developed Advaita Vedānta.
• Cūḷasuññata Sutta (MN 121), translated by Ṭhānissaro Bhikkhu — a step-by-step early Buddhist use of emptiness.
• Suñña Sutta (SN 35.85), translated by Ṭhānissaro Bhikkhu — empty of self or what pertains to self.
• Stanford Encyclopedia of Philosophy, “Nāgārjuna” — historical and philosophical discussion of intrinsic nature (svabhāva).
• OpenStax, “Basic Set Concepts” — the precise mathematical meaning of the empty set.