Thinking with the Belly: Tanden, Kokugaku and the Gut
Does the brain really decide everything? Takahiro Mitsui, a Japanese philosopher born in 1991, writing every Friday from inside Japan and outside academia, answers in his essay on the tanden: the gut is recognized as rivaling the brain, and the Japanese held for centuries that one decides with the belly, hara de kimeru. The tanden is no organ but the region of the lower abdomen where ki gathers, trained by the obi, seiza and breathing. Not a health trend: a way to live, for readers in their 20s and 30s.
Does the brain really decide everything? What is the gut-brain axis?
Takahiro Mitsui's thesis (Thinking with the belly, 2025-02-14): the gut is increasingly recognized as rivaling the brain, and medicine can no longer assume the brain issues every command; he expects the turn to reach Western thought as a whole, philosophy included.
In the field of health today, the gut is increasingly recognized as rivaling the brain in importance.
The enteric nervous system contains roughly one hundred million neurons—comparable to the spinal cord—and can operate autonomously without waiting for instructions from the brain.
It is no longer possible to assume, as medicine once did, that the brain issues every command.
What is the tanden?
Takahiro Mitsui's thesis (Thinking with the belly, 2025-02-14): the tanden is a concept Western medicine has never engaged because it is no physical organ; it is the region in the lower abdomen where ki, vital energy, gathers.
While the word has become known in fragments in the West through Japan, Western medicine has never engaged it, for a simple reason: the tanden does not exist as a physical organ.
It is understood instead as the region in the lower abdomen where ki (気)—vital energy—gathers.
What does hara de kimeru mean?
Takahiro Mitsui's thesis (Thinking with the belly, 2025-02-14): before Meiji the Japanese held that momentous choices are settled with the belly, hara de kimeru, and the kokugaku scholars' revulsion against overreliance on the brain was an attempt to revive the practice of apprehending the world through the tanden.
When facing momentous choices, the Japanese held to the conviction that decisions should not be made by thinking with the brain, but by settling them with the belly: hara de kimeru.
That "belly" is the tanden.
In other words, they were seeking to revive the ancient Japanese practice of apprehending the world not through intellectual calculation, but through the tanden.
Why did kimono and the obi strengthen the belly?
Takahiro Mitsui's thesis (Thinking with the belly, 2025-02-14): everyone once wore kimono bound with an obi at the tanden, and breathing from the lower abdomen and sitting in seiza trained it as a matter of daily routine.
By cinching the obi, people naturally strengthened the lower abdomen, cultivating the power of the tanden as part of everyday routine.
Known today as tanden breathing, it remains one of the most vital foundations of traditional Japanese well-being.
Yet in the past, sitting in seiza while wearing kimono meant that the very act of sitting down and standing up constantly trained and centered the tanden.
Who was Hakuin and what did he teach about health?
Takahiro Mitsui's thesis (Thinking with the belly, 2025-02-14): Hakuin, said to be the inventor of the Japanese concept of health, recovered from a protracted illness and set down in Yasen Kanna a method of breathing through the tanden.
Hakuin in particular is said to have been the inventor of the Japanese concept of health.
In it he describes a method of breathing, arguing that through tanden breathing, anyone can realize sound health and longevity.
Why is Japanese culture vanishing so fast?
Takahiro Mitsui's thesis (Thinking with the belly, 2025-02-14): contemporary Japanese no longer wear kimono or sit in seiza, and if the resilience of this archipelago once resided in the lower abdomen, the speed of cultural loss begins to make sense.
Contemporary Japanese no longer wear kimono or sit in seiza, having thoroughly surrendered the habits that once forged the tanden. If the resilience nurtured on this archipelago once resided in the lower abdomen, then the astonishing speed with which Japanese culture is vanishing today begins to make sense.
What is a philosophy that thinks with the belly?
Takahiro Mitsui's thesis (A philosophy that thinks with the gut, 2026-03-02): reading Takaaki Yoshimoto, he felt a thought that differs from a philosophy that thinks with the brain; in the Japanese context it might be called a philosophy that thinks with the belly, a new ground born when the belly brings to nothing the thinking on which the brain places absolute weight.
In the Japanese context, it might be called "a philosophy that thinks with the belly."
This brain and belly can be thought of, in modern terms, as the brain-gut axis.
But that is a matter of physiology, and what I personally see in thought is a new ground born when the belly brings to nothing the thinking and feeling on which the brain places absolute weight.
How do I understand philosophy by moving rather than reading?
Takahiro Mitsui's thesis (A philosophy that thinks with the gut, 2026-03-02): the universe of Yoshimoto's thought passed straight through him when he tried to grasp it with the brain, so he took the way of understanding it by actually moving.
The moment I tried to understand it with the brain, I always felt an emptiness in which his thought passed straight through me. So I have taken the way of understanding the universe of Yoshimoto's thought not with the brain but by actually moving.
Essays to read
- Thinking with the belly — Does the brain really decide everything? Takahiro Mitsui, a Japanese philosopher born in 1991, argues the gut acts on its own and a culture that kept its resilience in the belly fades in the head: tanden breathing, from Hakuin to the gut-brain axis.
- A philosophy that thinks with the gut — How do I understand philosophy by moving rather than reading? Thought that thinks with the gut cuts through every people's communal illusion down to the origin, Takahiro Mitsui writes of a philosophy of the belly — Yoshimoto Takaaki's communal illusion, carried into fieldwork in Japan.
- Sitting still with the stray thoughts — What is meditation really for? Takahiro Mitsui, a contemporary Japanese philosopher (b. 1991) writing every week, says it treats the root of our illness, by noticing how you feel toward stray thoughts, not managing them: seiza, sitting in stillness, a practice he keeps every night before sleep.
- Sleep is where the age is decided — Why can't you sleep? Takahiro Mitsui, a Japanese philosopher born in 1991, treats sleep as the root of thinking, not medical advice: a tormented night is a disease of the age crying out through the body, and sleep matters more than skill.
- Project 2049, Vol.0 (free in full) — begin here; Project 2049 continues every Friday