Tetsunori Koizumi, Director
Duality is a prevalent concept in science. An attempt to explain natural phenomena in terms of duality may be traced back to Aristotle when he explained the universe in terms of dual concepts of matter and forces, where matter consisted of the four elements of earth, water, air and fire, and forces of the two movements of gravity and levity. The Aristotelian idea of explaining the universe in terms of dual concepts of matter and forces was inherited by physicists, as witness the dual concepts of position and momentum employed in classical mechanics.
By far the most remarkable discovery of duality in the universe would be in the field of quantum mechanics known as the wave-particle duality. This is how that duality in quantum mechanics is explained by Stephen Hawking (1942 - ), one of the most remarkable physicists whose contributions range from cosmology to relativity to quantum mechanics: “Although light is made up of waves, Planck’s quantum hypothesis tells us that in some ways it behaves as if it were composed of particles: it can be emitted or absorbed only in packets, or quanta. Equally, Heisenberg’s uncertainty principle implies that particles behave in some respects like waves: they do not have a definite position but are ‘smeared out’ with a certain probability distribution. … There is thus a duality between waves and particles in quantum mechanics: for some purposes it is helpful to think of particles as waves and for other purposes it is better to think of waves as particles.”1
While duality in science is regarded as a useful, even essential concept in explaining natural phenomena, duality in Buddhist thought, as represented by the idea of existence and the idea of non-existence, is regarded as a concept that needs to be avoided. In the Samyutta Nikaya, for example, the Buddha explains duality as follows: “This world, Kaccana, for the most part depends on a duality—upon the idea of existence and the idea of nonexistence. But for one who sees the origin of the world as it really is with correct wisdom, there is no idea of nonexistence in regard to the world. And for one who sees the cessation of the world as it really is with correct wisdom, there is no idea of existence in regard to the world.”2
Why are there such sharp differences in the way the concept of duality is treated in science and Buddhist thought, despite parallels and similarities that exist between the scientific and the Buddhist view of the world? We must note, in the first place, that there is a semantic difference in the use of the concept. Although the same word is used, duality in science is used in the sense of “complementarity” to refer to two aspects of the same reality. Duality in Buddhist thought, in contrast, is used in the sense of “opposition” between two views about the nature of reality such as sassatavada (eternalism) versus ucchedavada (annihilationism) and atthita (the idea of existence) versus natthita (the idea of nonexistence). The so-called Cartesian dualism originally proposed by Rene Descartes (1596-1650) can be regarded as an example from the history of science in which the concept of duality was used in the sense of “opposition”, where mind and body were regarded as referring to two separate entities. Today, of course, most scientists have abandoned the Cartesian dualism between mind and body in favor of “holism”, Paul Davies explains: “Mind and body are not two components of a duality, but two entirely different concepts drawn from different levels in a hierarchy of description.”3 In addition to a semantic difference, there is, of course, a substantive difference between science and Buddhist thought as to what duality actually refers to. While duality in science refers to features of some physical entity in nature, duality in Buddhist thought refers to features of our conceptual understanding of the world around us.
Duality in science is treated as a useful concept because it gives us a complete picture of a natural phenomenon such as the position-momentum duality in classical mechanics or the wave-particle duality in quantum mechanics. On the other hand, duality is treated as something to be avoided in Buddhist thought because it represents two opposing and extreme views about the nature of reality in the world around us. Hence, the Buddha’s recommendation of the middle way: “‘All exists’: Kaccana, this is one extreme. ‘All does not exist’: this is the second extreme. Without veering toward either of these extremes, the Tathagata teaches the Dhamma by the middle…”4
Since duality is to be avoided, overcoming dualistic thinking becomes an essential aspect of Buddhist practice. That practice involves, for example, from the abandoning of unwholesome thoughts connected with lobha, dosa, and moha, or “greed, hatred, and delusion” to the cultivation of samatha and vipassana, or “serenity and insight”. In any event, we will be completely liberated from duality, or dualistic thinking, only when we obtain that clarity called enlightenment, as Master Sheng-yen explains: “It is like clear vision that is completely aware of what is in front: when this clarity is perfect, it has no likes or dislikes. Why? Because the essence of this clarity is nondual and itself has no likes or dislikes. … Complete Enlightenment is universally illuminating in quiescent-extinction without duality.”5
- Stephen W. Hawking, A Brief History of Time, New York: Bantam Books, 1988, p.36.
- Bhikku Bodhi, In the Buddha’s Words: An Anthology of Discourses from the Pali Canon, Boson: Wisdom Publications, 2005, pp.356-357.
- Davies, Paul, God and the New Physics, New York: Simon and Schuster, 1983, p.83.
- Bhikkhu Bodhi, op.cit., p.357.
- Master Sheng-yen, Complete Enlightenment: Zen Comments on the Sutra of Complete Enlightenment, Boston: Shambhala, 1999, p.26.