The question of the relation between the one and the many has shaped Western philosophy from its beginnings. ‘One’ or ‘many’? may sound like a simple question but it touches on two profound puzzles: how can unity and multiplicity coexist in a single (unified or multiple) reality? And, what is more fundamental – the one or the many?
I want to begin with a simple introspective contemplation – are you, dear reader, one or many? Please take a moment to feel your body before you answer this question. Notice your hands, feet, head, and internal organs. Each is a distinct part with its own specific function, yet all work together as one cohesive being to make up ‘you’. Acknowledge the cells and the neurons that make up your body. There are billions of individual components (the many), all functioning in harmony to create a single, unified entity you call ‘myself’ (the one).
‘One’ or ‘many’? is a question that can be posed in a more explicitly reflective, philosophical manner. A single tree (one) is nothing but thousands of constantly changing parts: individual leaves that grow, fall and decay; branches, cells, and so on. What is real – the whole or the parts? Does the tree exist as a unit or is ‘the tree’ just an idea, a name for many interrelated, continuously changing elements? Or does the tree as a whole reveal something that cannot be found in its parts? Is the whole more than the sum of its parts, as the famous saying goes?
These questions matter because they shape our understanding of the world around us. Biology is a good example of this: living entities, beings, and systems are often seen as reducible to their parts. The limitations of this approach can be found in evolutionary theory, medicine and public health. To begin with, every organism is a dynamic whole made up of countless of interacting cells, tissues, organs, microbiomes, chemical pathways, immune responses, and environmental inputs. If we treat these parts as isolated, we miss aspects of how these processes interact to keep an organism alive. For example, the heart is not just a pump. Its function depends on neural regulation, hormonal signalling, the availability of oxygen, emotional states, and even social context. This part-whole relation cuts across scales. A healthy person depends on the activity of their organs, cells, and molecules but their organs, cells and molecules in turn depend on being part of a living organism. Remove a cell from its environment and it will behave differently. Remove a person from a supportive social environment and mental or even physical health can deteriorate. Parts only function as parts of a larger whole, and the whole is constantly reshaped by its parts.
So, the part–whole problem is not an abstract metaphysical puzzle; it is a lived reality. How we answer these questions impacts our engagement with reality. Thinking that living beings are collections of parts may lead to reductionism. If, instead, we see the whole organism as something that emerges from but also shapes its parts, we may be more inclined to use systemic and processual explanations and pay closer attention to context and interaction. Modern biology has substantiated the intuition that the second (holistic) picture is at least as important as the first (reductive) one. Finally, if we think in terms of energy rather than in terms of static things, the connection between the one and the many becomes evident: living systems remain unified because countless processes transform energies across different scales to maintain the whole. Unity emerges from the energetic activity linking the many parts.
But this discussion of the relation between parts and wholes is only a version of a more general problem of the one and the many. While the parts-whole perspective explores the structure and composition of beings – and is easier to grasp – the more general ‘one-many’ perspective concerns the nature of reality more broadly. Is reality unified or multiple? This question can be asked in various forms – as a question of universals and particulars, substance and accident, Being and beings – or, as we have already seen, as a question of parts and wholes.
The more general one-many questions can be posed as: can unity contain multiplicity? If unity is a result of multiplicity, is it even a unity? Either something is one (i.e. has no parts) or it is a multiplicity. If it has multiple parts, it is clearly not one, but a multiplicity. At least that is the stance that Parmenides, a pre-Socratic Greek philosopher, took. For Parmenides, a thorough reflection on these issues could only lead to the conclusion that Being is absolutely One; it contains no parts, it doesn’t come into existence, it doesn’t change, and it can’t be divided – ultimately there is no plurality. Since you can’t think or speak about ‘what is not,’ he argues, anything that looks like change or multiplicity must be an illusion. The world of everyday experience, with its moving and changing bodies and shifting appearances, occurs at the level of opinion (doxa), not the truth.
Parmenides showed how the question of the one and the many relates to the question of stability and movement. If there is only the one, it cannot change – because then there would be multiplicity, a difference in the one, which means genuine oneness would not be present. Parmenides’ point is that nothing can simply pop into existence or vanish into nothingness. Heraclitus flips this picture around. He insists that the world is full of real multiplicity and constant flux, but he doesn’t think that this means that there is only chaotic multiplicity. Instead, everything is held together by a kind of underlying order or logos, a unity not as oneness, but as harmony that shows itself in the way opposites work together, like the tension in a bow or a lyre. For him, the world is one, but only in the sense that it’s a single, ever-unfolding process.
While Western philosophers kept moving back and forth on whether reality is ultimately one or many, Eastern philosophers – Mahayana Buddhist philosophers in particular – took a different, more paradoxical route. They considered one and the many to be interrelated and arising interdependently – no unity without plurality and no plurality without unity, while at the same time claiming that both are empty (not inherently existent). Masao Abe explains in Zen and Comparative Studies that
in dependent co-origination, it is not only that one and the many are dependent on each other in their arising and ceasing, but also that both one and the many are completely without substance and empty. Thus, it must be realized that although one is one as distinguishable from the many, one is not one: although the many is the many as distinguishable from the one, many are not the many. This is a realization that there is neither one nor the many.
In this framing there is no conflict, between the one and the many – one is not more fundamental than the other, because the one arises out of the interaction of the many, and the many continue in dependence on the one. The tree needs its leaves to continue to maintain itself and the leaves depend on the tree to receive and distribute nutrients. And at the same time both are thought to be empty of self or inherent existence.
When a Buddhist declares that ‘this object is empty,’ the point is not that the object is some kind of phantom, apparition, pure illusion without reality, or a dream. Nor is the object’s sensory and phenomenal identity denied. Buddhists do acknowledge that there is something that appears directly in experience. What is being denied rather is that whatever appears possesses an underlying, substantial identity that would exist apart from the object’s phenomenal appearance. In this sense, even if the sensory and phenomenal identity of an object can be affirmed with certainty, it is still said to be empty because it lacks a substantial or intrinsic self-identity. Again, Abe explains that
‘one’ does not exist apart from ‘many,’ just as ‘many’ is inconceivable apart from ‘one.’ ‘One’ and ‘many’ always co-arise and co-cease. Accordingly, an absolute ‘One’ which is aloof from ‘many’ is just as much a conceptual construction as a ‘many’ which is unrelated to the ‘One.’ In Buddhism the ultimate reality is neither the divine God who is absolutely one nor human beings who are multitudinous, but the relationality or ‘dependent co-origination’ of everything, including the relationality between one and many, God and humans.
Within this framework, there is thus no question of ‘one’ and ‘many.’ Both are just labels attached to a reality that is fundamentally interrelated and continuously becoming.
Tina Röck