Neil Theise is a diagnostic liver pathologist, adult stem cell researcher, and complexity theorist. He is a professor of pathology at NYU Grossman School of Medicine in New York City.
Below, Neil shares five key insights from his new book, Notes on Complexity: A Scientific Theory of Connection, Consciousness, and Being. Listen to the audio version—read by Neil himself—in the Next Big Idea App.
1. Complexity is the scientific theory of life.
Complexity theory was devised by mathematicians and computer scientists in the late 20th century and is one of the three pillars of modern science. While the two more famous scientific theories, relativity and quantum mechanics, are astonishingly successful at describing the vastest and the most infinitesimal aspects of the universe, it is complexity theory that helps us understand what we see in our everyday lives.
You may be thinking, isn’t biology the science of life? Yes, but biology is mostly reductionist, explaining the pieces of life. Biology breaks down large biological structures into smaller parts to learn how they function. In cell biology, for example, one dissects the body to examine tissues and organs and then disaggregates these into cells. In molecular biology, cells are broken apart to study their molecules. It’s akin to taking apart a clock or a car to figure out how it works.
The biological sciences have yielded tremendous benefits and will continue to do so at a dizzying pace, but biology has failed to explain the general principles that allow life to emerge in the universe, how life continues to change and adapt, how it’s always full of surprises, and life’s remarkable diversity. Whereas machines are precisely the sum of their parts, biological systems are always more than the sum of their parts.
That is the work of complexity theory: how all those parts organize themselves into the larger scale structures or systems of the world, how molecules interact to become cells, how interacting cells become tissues and organs and bodies, and how interacting bodies become ant colonies or flocks of birds or city neighborhoods or human cultures or the whole global ecosystem. Complexity theory tells us about how the whole of life works overall.
Only with complexity theory do we get to name the precise rules through which complex life arises and adapts. Profound implications flow easily from these principles. So easily that I’ve described them not only to scientists at the highest level of training but to Zen students and practitioners of yoga and even to my nephew’s fifth-grade class, not needing to simplify the language at all to get the points across.
2. All living things follow the same four complexity rules.
All living things, from the smallest levels of molecules and smaller still, all the way up to the global scales of the earth’s ecosystem and beyond, self-organize by obeying four simple rules.
One: the more interacting parts, cells, ants, people, and the greater their diversity, the greater the complexity of the resulting system, bodies, ant colonies, cities, cultures, and civilizations. A single-cell organism is not as complex as a multicellular one. A village is not a city is not a megalopolis, but the same rules apply no matter how large and how complex.
Two: in self-organizing systems, all interactions are local. Ants meet the pheromone signals of other ants. Humans connect to the social, linguistic, and physical cues of other humans. There is no top-down organization. There is no all-knowing individual or entity or queen directing the participants. Organization always emerges from the bottom up.
“Negative feedback loops must predominate for healthy living things.”
Three: negative feedback loops keep systems healthy. Positive feedback loops exist, but they cannot predominate. A space heater is an example of a negative feedback loop. When the room gets cold, it turns on. When the room warms up, it turns off. Positive feedback? Imagine if the warmer a room got the more the heater cranked up. Negative feedback loops must predominate for healthy living things.
Four: there must be some low-level randomness or unpredictability in every living system. Too much and there can be no self-organization, no greater whole. Too little and the system is unable to adapt if the environment changes. For adaptation that allows the resilience and continuity that is the hallmark of life, there must be a narrow range of unpredictability. This is the driver of life’s creative dynamism. In every moment, random potentials create a shimmering cloud of possibilities for what the next moment might be. They arise from unpredictable, often small behaviors in this moment. They can never be predicted in the next. This is why life, your life, my life, all lives are unpredictable moment to moment as they unfold.
3. Everything only looks like a thing.
Every thing, every object, only looks like it’s a thing—as something real in itself. Let me explain, using ants as an example.
Ants follow all four rules of complexity. They self-organize from the bottom up into the larger scale structures of the colony, the food lines, the nursery, the garbage dump, and the cemetery. No ant is monitoring the colony as a whole or planning these structures top-down. Negative feedback loops in the form of scent trails that degrade over time keep exhausted food lines from going on endlessly after the food runs out and a small number of divergent ants (the ones not following the food line) are most likely to find the next food source.
Let’s say you’re walking in the desert and you see a dark shape on the ground in the distance. You may not be sure what it is, but it certainly looks like a thing. When you get close enough, you see that it’s not a thing at all. It’s ants. The thingness was an appearance only seen from a distance. Up close, the same thing gives way to a phenomenon arising from smaller things, the ants themselves.
Now zoom in closer to the cellular level. At that distance, the ant itself disappears. There is no ant body. There is only the intricate dance of cells interacting with each other. Whether something looks like a thing or is a phenomenon arising from interacting smaller things depends on our perspective, the level of scale from which it is viewed.
Are cells irreducible things? The cell doctrine of Western biology says they are. As a diagnostic pathologist, I spend many hours a day at the microscope gazing at human tissue at the cellular level to make clinical diagnoses. But cell doctrine is only true from the microscopic perspective. At the nanoscopic level, the cell disappears as a thing and is just self-organizing molecules that float in water. Are molecules things? No, they are self-organizing atoms. Are atoms things? No, just self-organizing subatomic particles, and so on.
“Whether something looks like a thing or is a phenomenon arising from interacting smaller things depends on our perspective.”
While quantum physicists may disagree about what the smallest things are, there is consensus that there isn’t an infinite regress to smaller things. It is also agreed that space-time itself, the fabric of the universe, is not empty or smooth, but a roiling energy-rich field. Thanks to Einstein, E=MC2, we know that this energy is constantly emanating onto small entities with mass, whatever they are. Usually it does so in matter- anti-matter pairs, which immediately self-annihilate, subsiding back into the energetic field of space-time. This process is referred to poetically as the quantum foam.
But sometimes matter-anti-matter pairs don’t self-annihilate. Sometimes these smallest entities interact, a quantum level example of low level unpredictability, and they self-organize into subatomic particles and thence into atoms, into molecules, and then into the whole vast structure of the entire universe, including you and me.
Complexity theory thus reveals how the whole universe is one vast complex system emanating from out of space-time itself. There is no actual thing to be found anywhere at any scale. Everything is only process, only interaction, and so everything only looks like a thing.
4. The universe is a boundless body.
On the everyday scale, you and I are separate. Here I am bounded by my skin and there you are bounded by yours. All beings seem separate, but are they? Whether something appears to be a thing or a phenomenon depends on scale. So, too, do our boundaries shift as we change our view. At the cellular level, we now know that our bodies are not just composed of human cells, but an equal number of non-human cells, mostly bacteria.
This community of cells, called the microbiome, is as integral a part of our human bodies as our own cells are. Without them, our skin’s protective barriers crack wide. Our ability to absorb food collapses and our immune systems begin to fail. They are our bodies as much as our human cells are, and when we touch any surface, we leave some of our cells behind for someone else to pick up. When we shake hands, hug, or kiss, we exchange cells.
In fact, in a household of people and their pets, the household is a single giant microbiome that merely clusters around each human, dog, and cat. No separation. At the cellular level, our boundaries are the rooms we share with our families, friends, colleagues, and pets.
At the molecular level, our boundaries extend even further. Just think about the carbon dioxide we share with plants and the oxygen they share with us. This is merely one example of how we are truly one with the entire biomass of the global ecosystem.
At the atomic level, is there any atom in our bodies that we didn’t drink, eat, or breathe from the planet? Are we separate little creatures scurrying around on the surface of this rock we call Earth, or are we the atomic substance that over three and one half billion years has self-organized into creatures that ponder these questions while assuming they’re separate?
“Is our body a thing or a phenomenon arising from smaller things? It is both, a complementarity.”
At the atomic level, our boundary is as large as the entire planet, and when one goes down to the subatomic or quantum level, the domain of non-locality and quantum entanglement, there is no separation anywhere, just as there are no true things. Our boundaries are the furthest reaches of the universe. Thus, the universe is a boundless body, and our sense of separation only specific to our habitual perspectives.
This dependence on perspectives can be summarized in a useful term: complementarity. You may have heard of quantum complementarities, such as light being either waves or particles depending on how it is viewed. If the light is viewed by a conscious observer, it behaves like particles, photons. If it is not, it behaves like waves.
In complexity, we find examples of complementarity in living things. Is our body a thing or a phenomenon arising from smaller things? It is both, a complementarity. Are we lonely beings living in a vast empty universe, or are we the universe itself differentiating within itself? A complementarity. These are not either/or propositions. They are always both/and. Thus, complexity theory teaches us not only that we are never separate from others, indeed from all existence, but that if we cling too tightly to any single view, we are missing at least half of the true nature of reality.
5. Metaphysical intuitions are valid roots to understanding the true nature of reality.
We live in a materialist culture. Materialism tells us that the world is purely material, made of matter and energy. It also tells us that empirical sciences and formal mathematics are the only tools with which we can discern the true nature of reality.
Quantum physics, however, undermines the materialist worldview. The wave particle duality of light, the ultimate example of the importance of perspective, famously led Max Planck, one of the founders of quantum mechanics, to say one cannot get behind consciousness. The suggestion here is that consciousness comes first, with perceived material existence following it. Most of the other founders of quantum physics agreed with Planck.
Complexity theory likewise undermines the material nature of existence. It shows that thingness, boundaries, and materiality are dependent on the scale of observation. Unresolvable complementarities abound not only in the quantum realm but across all scales.
From the mathematical perspective, Kurt Godel, the greatest logician of all time with his incompleteness theorems, proved that there were truths about the universe that could be known to be true, but could not be proven to be true. Their truth could only be realized through intuitions and so metaphysical meaning derived from deep contemplative practices of turning the mind inward to explore itself were brought to the table as tools to understand the true nature of reality. Insights from some meditative traditions yield a view of the universe that aligns with the assumption that consciousness is the source of space-time itself and all that arises from it.
All of these conclusions have been life transforming for me. Not mere ideas, but new ways to understand our relationship to existence, to find meaning, and to cultivate resilience in the face of the inevitably shifting nature of life. Notes on Complexity takes us on an unexpected journey, one that begins with math, but ends with meditation and mind.
To listen to the audio version read by author Neil Theise, download the Next Big Idea App today: