One key teaching of Buddhism is that there is no independent existence. This is called the doctrine of Anatta (no-self). How can you discover that you have no self? Let’s do a thought experiment. Consider the internal organs of your body. Your brain and your heart are both parts of yourself, right? Neither the brain nor the heart can live alone. They cannot exclude each other, and one cannot claim superiority over the other. It seems fair to say that something is part of yourself if you cannot survive without it. Now, expand the boundary of yourself. Can you still exist if all the bees are gone? The extinction of the bees would mean that a major pollinator would be gone. This has ominous consequences on the food chain. Can we survive that? Now, repeat the question with other natural objects. Can you still exist if all the fish are gone? Can you still exist when all the trees are gone? When clean air is gone? When the rivers and streams are gone? When the sun is gone? Certainly not! My existence depends on all these things. We are an ecosystem. The boundary of yourself can be expanded indefinitely because even distant objects such as the sun, the moon, and the stars are vital for your existence.
Now, do the experiment in the other direction. Instead of expanding the boundary of ourselves outward to the stars, focus your attention on what is happening on a microscopic level. Modern medical research has drawn our attention to the importance of our microbiome. According to the Merriam-Webster Dictionary, the microbiome refers to “a community of microorganisms(such as bacteria, fungi, and viruses) that inhabit a particular environment and especially the collection of microorganisms living in or on the human body. The Harvard School of Public Health issued a report which highlights the importance of the microbiome in our bodies:
These (microorganisms) include not only bacteria but fungi, parasites, and viruses. In a healthy person, these “bugs” coexist peacefully, with the largest numbers found in the small and large intestines but also throughout the body. The microbiome is even labeled a supporting organ because it plays so many key roles in promoting the smooth daily operations of the human body.
What are some of the health benefits of the microbiome? The Harvard report contiues:
Microbiota stimulate the immune system, break down potentially toxic food compounds, and synthesize certain vitamins and amino acids, including the B vitamins and vitamin K. For example, the key enzymes needed to form vitamin B12 are only found in bacteria, not in plants and animals.
How numerous are these microorganisms in our bodies? The following is reported in the April 11, 2018 issue of Science Alert:
(Ron Milo and his research team) found that for a man between 20 and 30 years old, with a weight of about 70 kg (154 pounds) and a height of 170 cm (about 5'7) — they call him the ‘reference man’ — there would be about 39 trillion bacterial cells living among 30 trillion human cells. This gives us a ratio of about 1.3:1 — almost equal parts human to microbe.
Thus, microbes outnumber our own body cells by a ratio of 1.3 to 1. But if they are so vital to our well-being, shouldn’t we consider the microbiome also a part of ourselves? Continuing on a microscopic level, let us consider further the boundary between ourselves and others. Instead of investigating on the cellular level, we shrink even further into the organelle level. Remember the mitochodria, the little power engines inside our cells? The Feb. 18, 2016 issue of Science Magazine had an interesting article which ponders the origin of these tiny cellular structures. As it turned out, the mitochondria have an “alien” origin — they were originally not parts of us, but were foreign bodies. The article asks a series of interesting questions:
It’s one of the big mysteries of cell biology. Why do mitochondria — the oval-shaped structures that power our cells — have their own DNA, and why have they kept it when the cell itself has plenty of its own genetic material? A new study may have found an answer.
Scientists think that mitochondria were once independent single-celled organisms until, more than a billion years ago, they were swallowed by larger cells. Instead of being digested, they settled down and developed a mutually beneficial relationship developed with their hosts that eventually enabled the rise of more complex life, like today’s plants and animals.
It should be clear now that there is no clear boundary between “us” and the rest of the world. Our “selves” have incorporated foreign organisms and made them part of “us.” Can you imagine living without the mitochodria? How would your body generate energy then?
Given these considerations, who can we say we are? It seems fair to say that we are the universe. Our existence depends on the planet and the stars. It also depends critically on certain priviously foreign substances. The boundary between self and others is blurry and amorphous. In a literal sense, we are the universe. Alternatively, we can also say that we are nothing. Scientifically speaking, the self is ill-defined.
The Buddha taught that there is no self. We have just seen that this is a true statement from a scientific perspective. Regardless of whether we consider the matter from a macro perspective or from a micro perspective, there is no self. Or all is self. It is the same thing! Personally, I prefer a term Zen master, Thich Nhat Hanh, uses — “Interbeing.” We are Interbeings.