Emptiness (sunyata)

Sunyata is regularly mistranslated into a claim that nothing exists, and the tradition anticipated the error and spent a great deal of effort on it. Emptiness is not a substance, not a void, and not nothingness. It is a property, and the property is a lack: things lack svabhava, own-being, inherent existence, a nature they possess independently of causes, conditions, parts and conceptual designation.

Nagarjuna, writing in the second century, established the position by argument rather than assertion. His method in the Mulamadhyamakakarika is to take each candidate for inherent existence, causation, motion, time, the self, the aggregates, the Buddha, nirvana, and to show that every available account of it as independently real collapses into contradiction. He then identifies emptiness with dependent origination, the doctrine already central to earlier Buddhism: to arise in dependence on conditions just is to lack inherent existence. That equivalence is the hinge of the whole system, because it means emptiness is not a denial of the world but a description of how the world is.

Two safeguards are built in. The first is the two truths: conventionally, things exist, function, and can be spoken about truthfully, and Nagarjuna insists that without conventional truth the ultimate cannot be taught. The second is that emptiness is itself empty. It is not a hidden absolute underlying appearances; treating it as one is the error the texts warn against most sharply, with the image of a medicine that kills if it is not itself expelled.

The earlier tradition had applied the analysis of no-self to persons. Mahayana extends it to all phenomena, including the elements into which the earlier Abhidharma analysis had resolved experience.

Emptiness is common ground across Mahayana and the starting point of its internal arguments rather than the end of them.

Madhyamaka, Nagarjuna's school, holds that the correct position is the absence of any position: it advances no thesis about what ultimately exists and works by dismantling the theses of others. Later Tibetan scholastics divided this further, between those who thought the analysis could be set out in formal argument and those who held it must proceed only by drawing out the consequences of an opponent's own premises.

Yogacara developed a different account, analysing experience into three natures and arguing that what appears as an external world is a construction of consciousness. Its relation to Madhyamaka has been argued about for fifteen centuries, some reading the two as compatible descriptions at different levels, others as rivals.

The Tathagatagarbha or Buddha-nature literature poses the sharpest question, because it speaks of something permanent, blissful and pure within all beings, which reads as an affirmation of exactly what emptiness denies. Tibetan traditions divide on it: the position known as emptiness of other holds that the awakened nature is empty of defilements but not of itself, while the dominant Gelug position insists that Buddha-nature must be understood as emptiness itself and rejects any reading that reintroduces an inherently existing ground.

The comparison worth drawing is with Advaita Vedanta, which is often assimilated to emptiness in popular writing and is close to its opposite. Advaita affirms one absolutely real thing, Brahman, and holds the world of distinctions to be superimposed on it. Madhyamaka denies inherent existence to everything, including any absolute. Shankara accused Buddhists of nihilism; Buddhist opponents accused Advaita of smuggling back the self that the whole tradition was founded on denying. Both charges were sincere.