IT HAS BEEN SAID THAT, after the Buddha, the single most important figure in the entire Buddhist tradition was a monk named Acharya Nagarjuna, sometimes called the Second Buddha. As is the case with many religious giants, we know little about the historical Nagarjuna. Scholars usually place him sometime in the late second century C.E., but he may have lived a hundred years before or after that period. According to tradition, Nagarjuna was a scholar-monk at Nalanda University, the great Buddhist center of learning in northeast India. Although we know him through his body of writings, we don’t really know how many “Nagarjunas” there actually were, for it is unlikely that all the works attributed to him were written by the same person. There may well have been three or four monks all writing under the same name.

We do know that Nagarjuna’s writings are the basis for the Madhyamaka, or “Middle Way,” school of Buddhism and that Nagarjuna himself became the most influential figure in the development of Mahayana Buddhism, which had begun to emerge during the first century B.C.E. out of disagreements within the Indian sangha about the path to enlightenment. This is despite the fact that his writings never mention many of the signature Mahayana ideas, such as the bodhisattva ideal or the identity of form and emptiness. This raises the intriguing possibility that this pivotal figure in the rise of Mahayana may not himself have been a Mahayanist.

The most famous by far of all the writings attributed to Nagarjuna—and, not incidentally, the most important philosophical text in the Buddhist tradition—is the Miziamadhyamakakarika (“Root Verses on the Middle Way”). The Karikas, as they are often called, are composed of about four hundred and fifty short stanzas, which were eventually divided into twenty-seven chapters. These chapters address the major philosophical issues of his time—including the nature of causality and conditionality, motion and action, the self, its suffering and bondage, nirvana, and the Buddha—but Nagarjuna’s profound insights have proven to be timeless.

Unfortunately for the general reader, Nagarjuna’s Sanskrit, although not lacking in grace or precision, is impersonal and dense. The Karikas were meant to be memorized rather than read, and they would normally have been supplemented by the oral commentary of a teacher. But even then, Nagarjuna’s philosophy is notoriously difficult to understand (which might help explain why he is more revered than studied).

Some Buddhists might think of such a philosophical investigation as incompatible with their contemplative or devotional practice. But that is like separating meditation from wisdom. Absorption in one’s meditation practice develops calmness and clarity, yet peace of mind by itself is not the goal of the Buddhist spiritual path. Buddhism also emphasizes insight—seeing through the thought-constructions that our minds are usually stuck in—and it is these forms of reified thought that Nagarjuna deconstructs.

Nagarjuna’s philosophical approach was revolutionary, but he probably did not think of himself as a radical, which may be why he did not emphasize the Mahayana connection. His innovations are firmly rooted in the original teachings of the Buddha, who refused to discuss metaphysical questions. The Buddha said that debating such issues as whether the world had a beginning or not or what happens to an enlightened person after death was like being struck by an arrow and refusing to be treated until one knows what wood the arrow was made of, who shot it, and so forth. Instead of offering a speculative explanation of the world, the Buddha’s approach was pragmatic. He compared his dharma to a raft, which should wisely be used to cross the river of life and death. Once having crossed, however, one should not carry it everywhere on one’s back. Nevertheless, in the years after the Buddha’s passing, the compilers of the Abhidharma (“higher teaching”) extracted a metaphysics from his teachings.

We might regard Nagarjuna’s philosophy as linguistic therapy: it uses language to reveal how language deceives us. We assume that the world we experience is the real world, but this is delusion. The world as we normally understand it is a linguistic construct. Clinging to conceptual elaborations (prapancha) causes suffering, for they do not accurately reflect how the world actually is. As it turns out, our common sense view of the world is not commonsense at all, because an unconscious metaphysics is built into the ways we ordinarily use language.

Nagarjuna’s rigorous logic analyzes these ways of thinking and reveals that they are inconsistent and self-contradictory. By his own account, that is all he does. He does not try to replace our deluded ways of thinking with a correct understanding with which we can identify. Instead, the true nature of things (including ourselves) becomes apparent when we let go of our delusions. Our emotional and mental turmoil is replaced by a beatitude or serenity (shiva) that cannot be grasped but can be lived.

Buddhism is “the middle way,” yet that has meant different things at different times. The Buddha discovered a middle way between hedonism and asceticism. He also taught a middle way between eternalism (the self survives death) and annihilationism (the self is destroyed at death), for there is no self and never has been. Nagarjuna elucidated a middle position between being (things exist) and nonbeing (things do not exist). That middle position is shunyata. usually translated as “emptiness.”

Shunyata does not mean nonexistence or a void, nor does it describe some transcendent reality such as brahman or God. Shunyata simply signifies that things have no self-being or “essence” of their own. Everything arises and passes away according to causal conditions. For Nagarjuna, shunyata is a heuristic concept, a shorthand device used to refer to this absence of self-existence. Yet the term is often misunderstood. For some, shunyata means that nothing whatsoever exists in any way. Such nihilism is dangerous, because then it makes no difference what we do or do not do, and there is no point in trying to follow a spiritual path. This misconstrues Nagarjuna’s basic project, which is not to describe the world but to refute the ways in which we (mis)understand the world.

Nagarjuna was scathingly critical toward those who interpret shunyata as nothingness: woe to those who hold it, for it’s like grasping a snake by the wrong end. They confuse two different levels of truth, the conventional (samvriti) and the ultimate (paramartha). The conventional is not ultimately true, but it’s needed in order to point to the ultimate. Shunyata is a conventional truth that helps us realize the ultimate, which cannot be expressed in words. Shunyata is itself empty, but it is useful only for pointing out that nothing has self-existence. Shunyata helps pry us free from our attachment to things. But since shunyata has meaning only in relation to something that is not empty, and since ultimately there are no self-existing things, there is therefore no shunyata, either. As with the Buddha’s raft; we need to let go of shunyata, too. The “ultimate truth” does not refer to some other transcendent reality. As another Madhyamika, Atisha, later expressed it: “If you use reason to examine the conventional world as it appears to us, you can find nothing that is real (that has self-existence). That not-finding is itself the ultimate.”

Nagarjuna addressed the philosophical controversies of his day, but the theoretical positions he criticized were based on ordinary ways in which we humans understand ourselves and our world. Our basic delusion is the taken-for-granted distinction between things and their activities. Deceived by language, we divide up the world into nouns and verbs, subjects and predicates. We understand the world as a collection of separate things, interacting in external space and time, arising and passing away. This delusion includes the way we think about ourselves, of course. We usually distinguish our self from our actions and from the events that happen to us—including illness, old age, and death, the classic examples of suffering that inspired the Buddha’s spiritual quest. Because we think of our own being as separate from events, and from everything else, we anticipate with dread the inevitable fate that awaits our individual selves.

AGAIN AND AGAIN in different ways, the Karikas refute this thought-constructed distinction between objects and processes by analyzing how that very distinction distorts our understanding of causality, motion, perception, time, and so forth. Nagarjuna’s basic approach is almost always the same: The particular distinction being examined is shown to be incomprehensible, because, having been made, the two different terms no longer fit back together. The basic problem, the source of our suffering, is that our commonsense ways of understanding ourselves as separate from but also in the world assume this delusive distinction.

For example, consider the relationship between the self and its ever-changing mental and physical states (one’s thoughts, emotions, bodily feelings, etc.). Is the self the same as those states, or different from them? We say, “I am hungry or angry, or confused,” which implies that “I” am constantly changing. But we also have a sense of an “I” that persists unchanged: the “I” that works is the same “I” that gets a paycheck at the end of the month. In everyday life we constantly fudge this inconsistency. Sometimes we understand ourselves one way, sometimes the other, but understanding ourselves as things that both change and stay the same is really a contradiction. Nagarjuna’s explanation for the inconsistency is that the self is shunya, “empty.” In modem terms, my sense of self is an impermanent, ever-changing construct.

Nagarjuna also applies his method to Buddhist constructs. What about nirvana? It too is a shunya concept. If nirvana is something causally unconditioned, a reality that does not arise or pass away, then there is no way for us to get there. If it is conditioned, then it too will pass away, like every other conditioned thing. Neither alternative provides spiritual salvation. Letting go of the ways of thinking in which we are normally stuck allows us to experience the world as it really is. This, “the end of conceptual elaborations (prapancha),” is how Nagarjuna refers to nirvana.

Nagarjuna never actually claims, as is sometimes thought, that “samsara is nirvana.” Instead, he says that no difference can be found between them. The koti (limit, boundary) of nirvana is the koti of samsara. They are two different ways of experiencing this world. Nirvana is not another realm or dimension but rather the clarity and peace that arise when our mental turmoil ends, because the objects with which we have been identifying are realized to be shunya. Things have no reality of their own that we can cling to, since they arise and pass away according to conditions. Nor can we cling to this truth. The most famous verse in the Karikas (25:24) sums this up magnificently: “Ultimate serenity is the coming-to-rest of all ways of ‘taking’ things, the repose of named things. No truth has been taught by a Buddha for anyone anywhere.”

The methodological thoroughness with which Nagarjuna uses concepts to undermine the thought-constructed ways in which we understand the world has long led critics—Buddhist and non-Buddhist, Eastern and Western—to accuse him of nihilism. Indeed, it is likely that the Yogachara school of Buddhism, which emphasizes the reality of consciousness, arose partly as a response to such nihilistic interpretations. Evidently some later Buddhist thinkers were concerned that Nagarjuna’s exclusively negative approach—using language solely to remove the delusions created by language—needed to be supplemented by more positive descriptions of the Buddhist path and goal. Eventually the Madhyamaka and Yogachara approaches became understood as complementary, providing what is generally accepted as the basic philosophy of Mahayana.

David Loy is Besl Professor of Ethics/Religion at Xavier University and a Zen teacher.