Nondualism was developed earliest, and was most thoroughly explored, in India. Yet the first Indian scriptures, the Vedas (roughly 1000 BCE) are completely dualistic in their outlook. These Ur-texts of human spirituality consist mainly of poems of praise to nature deities, magical spells, and ritual invocations. After the Vedas, however, we find several important texts that contain what can be clearly understood as a nondual perspective: the Upanishads. There are only twelve main Upanishads, some very short, and yet in these texts we find the fundamental basis of Indian thought and religion. Here we find the first mention of such core concepts as karma, samsara, atman, moksha, and Brahman.
The Upanishads also show the beginning of investigation into and commentary on nondual awareness (as well as other mystical topics), and are notably different in tone and flavor from the dualistic ritualism of the Vedas. Because both Buddhism and Advaita Vedanta stem from these reflections, the Upanishads form the basis of what was later to become the greatest flowering of nondualism the world has ever seen.
We can think of the Upanishads as the philosophical addition to the Vedas, because the Upanishads delve into deep, metaphysical questions. The Sanskrit word upanishad literally means “sitting beside,” which implies that the texts contain the secret, sacred knowledge, which was originally imparted only verbally from teacher to student. Some of these metaphysical “secrets” show the beginnings of a description of nondual wisdom. Here is an example (from the Mandukya Upandishad [800 BCE] ):
Turiya is not that which is conscious of the inner (subjective) world, nor that which is conscious of the outer (objective) world, nor that which is conscious of both, nor that which is a mass of consciousness. It is not simple consciousness nor is It unconsciousness. It is unperceived, unrelated, incomprehensible, uninferable, unthinkable and indescribable. The essence of the Consciousness manifesting as the self in the three states, It is the cessation of all phenomena; It is all peace, all bliss and non-dual. This is what is known as the Fourth (Turiya). This is Atman and this has to be realized.
This quote is describing the turiya state, which means the “fourth” state.1 This text is the first place where we find this important term. This Upanishad seems to clearly describe both nirvikalpa samadhi (“it is the cessation of all phenomenon”) and nondual awareness (“it is good and nondual”), even going so far as to use the word “nondual.” The Upanishad begins by talking about AUM (which is a mantra found in the Vedas) and relates it to brahman (“nondual reality” or “God” depending on the reader), as well as atman (“soul”).
So in a very concise way, the author tells us that the soul and nondual awareness are the same thing, and both are identical to the entire universe. It is no surprise that the Mandukya Upanishad2 later (around 600 CE) becomes the source or root text of the Hindu Advaita (nondual) movement, as we will later see.
Often the idea of God is a central concept in nondualism. And here in this Upanishad we see that to be the case. Brahman can be thought of as God. In this formulation, we can say that the soul (atman) is the same as God (brahman) and that both are equivalent to the universe. If the whole universe and everything in it is none other than God, then that is a nondual universe. There are no opposites and therefore no dualities. You can see in this first known description of the nondualism how very different it is from standard, dualistic Western religious conceptions. We’re not in Kansas anymore.
Nondualism in the Upanishads is discussed in two rather contrasting ways, which we can refer to by their Latin names, via positiva and via negativa (“the positive way” and “the negative way”). Although these appear to be opposites, they actually represent alternate routes to exactly the same destination.
One example of the via positiva version of nondualism comes from the Isa Upanishad.3 This Upanishad goes into a detailed description of atman (“Self”), saying:
6: The wise man beholds all beings in the Self, and the Self in all beings; for that reason he does not hate anyone.
7: To the seer, all things have verily become the Self: what delusion, what sorrow, can there be for him who beholds that oneness?
This is a fair description of nondual awareness. If everything is composed of the same substance, how can there be any opposites?
Probably the most famous statement of the same viewpoint comes from the Chandogya Upanishad4 where it is said, “Thou art That” (Skt: tat tvam asi). This statement is first delivered from a father to his son in the text, but then becomes the refrain or chorus for the rest of the Upanishad, and later goes on to become virtually a defining statement of Advaita Vedanta. “Thou art that” is literally saying, “No matter what you see, it’s really just you.” So this is a positive way of looking at it: everything is you. God is you. You are God. The chair is God.
The classic statement of the via negativa approach appears in the Brihadaranyaka Upanishad5 (“Great Forest Text”), which is one of the oldest (c. 10th–5th century, BCE) and most important. Here we find the famous definition of Brahman as neti-neti “not this, not that.” Neti-neti means that Brahman can only be defined by what it is not, and what it is not is any thing. It is not any of the names or forms of this world. “Neti-neti” is literally saying, “No matter what you see, it’s really just God.” The chair isn’t a chair. You are not you. You’re both just God.
This definition, which sounds like the opposite of Brahman being the whole universe, is actually identical to brahman being the whole universe, because—in this way of looking at it—everything in the phenomenal universe is an illusion, including your separate self. Brahman is the reality that underlies the apparent, illusory world. Therefore everything in the universe is God. The idea of Brahman as neti-neti becomes a very strong theme in later Advaita Hinduism, both as a concept and as the root of practice.
Thus we see the beginnings of the notion of nondualism in the Upanishads. India in the first millennium BCE was awash in philosophical speculation, most of it fueled by the many hermits and ascetics doing meditation practices off in the jungles and mountains. Previously the Vedic priests had performed their rituals publicly and in large groups6 with the intention of creating merit that would allow them to go to heaven in the afterlife. Vedic thinkers eventually became concerned about the possibility of using up or losing this merit in the afterlife. They believed that residence in heaven might be a temporary state, and that when one’s religious merit ran out, one would experience the greatly-feared “re-death” (Skt: punarmrityu), and subsequent loss of the felicities of heaven.7
Some Vedic thinkers (particularly in the Brahmana texts) attempted to solve this spiritual conundrum using further ritual, magical means. The authors of the Upanishads, however, took a radically new approach which seems to have arisen from an equally-radical new experience. Instead of thinking up ever-more elaborate rituals, the upanishadic seers emphasized the cosmic connection behind the ritual. They saw that Brahman and Atman were identical, and therefore heaven could never be lost. Furthermore – and much more importantly – if Brahman and Atman are identical, the need for the ritual itself disappears. Rituals are just God worshipping God, so what’s the point? And so the writers of the Upanishads gave up ritual and public sacrifice altogether, and went into seclusion to seek an experience of the union of Brahman and Atman through meditation. We can see this as the beginning of a tradition of intentionally seeking out nondual awareness and of the philosophical speculation about nondualism.
It is interesting and important to remember that the historical Buddha was himself born a Hindu, and was raised in a highly educated Hindu family. He almost certainly would have been taught these Upanishads as a student, and been educated as to their philosophical import. When he eventually left his father’s palace to seek enlightenment, he may not have seen himself as starting a new religion, but merely continuing in the forest-meditation tradition of the seers of the Upanishads, which was in its heyday during his lifetime. His biographies tell us that he went forth seeking an end to suffering and death, which was exactly the goal of both the rituals of the Vedic priests and the meditative inquiry of the seers of the Upanishads.8
This is an excerpt from Michael W. Taft’s book on the history of Nondualism.
1 The other three are waking, dreaming, and deep sleep.
2 Read the full text of the Mandukya Upanishad here.
3 Read the full text of the Isa Upanishad here.
4 Read the full text of the Chandogya Upanishad here.
5 Read the full text of the Brihadaranyaka Upanishad here.
6 For example, the most famous mantra of the Vedas—the Gayatri Mantra—uses the plural form “we.”