The gut has it’s reasons

On walking, instinct, and intuition

First published on Substack.

“Go with your gut.” We offer it as advice, as permission, as reassurance. Trust your instinct over deliberation. Trust your feelings over your brain. It’s advice that spans cultures and centuries: in moments of uncertainty, stop overthinking. Trust your first instinct. Listen to something that isn’t rational. 

What kind of knowledge travels by feeling rather than by argument? Is it mystical nonsense or genuinely informative? 

Seventeenth-century philosopher and mathematician Blaise Pascal wrote in the Pensées (Thoughts): “The heart has its reasons, which reason does not know. We feel it in a thousand things.” We have long recognised, even if we couldn’t explain it, that there is a way of knowing that operates below and alongside conscious deliberation. 

What the gut knows, how it comes to know it, and under what conditions we are most able to hear it are questions that a brain tumour patient named Elliot and a neurologist would provide some insight into.

In the early 1990s, Antonio Damasio encountered Elliot, a successful professional whose life was altered by a brain tumour and the surgery required to remove it. The tumour was gone, but Elliot had changed.

Elliot’s intelligence was intact. His memory, language, reasoning, and attention all tested as normal. He could discuss a complex problem with fluency and care, turning it over from multiple angles, identifying relevant considerations, and articulating trade-offs with precision. What he could not do was decide.

Elliot struggled to experience emotion, which hindered his ability to choose between options. Damasio proposed that decision-making involves sensing how our body feels about different choices, but because Elliot could not feel, he was unable to make decisions.

He wasn't irrational; if anything, he was perhaps too rational. He is a living example of paralysis by analysis. As neuroscientist Damasio concluded, what he truly lost was the felt sense of preference. The gentle pull towards one option and the faint unease about another. Without that inner signal, rational analysis can become frictionless and endless, leading nowhere.

Damasio described the tragedy of Elliot’s interior life:

Try to imagine not feeling pleasure when you contemplate a painting you love or hear a favorite piece of music. Try to imagine yourself forever robbed of that possibility and yet aware of the intellectual contents of the visual or musical stimulus, and also aware that once it did give you pleasure. We might summarize Elliot’s predicament as to know but not to feel.

Damasio’s Somatic Marker Hypothesis suggests that bodily sensations, called somatic markers, influence decision-making, especially in uncertain situations. Physical feelings like a rapid heartbeat, nausea, sweating, or butterflies serve as “go” or “stop” signals connected to previous experiences. They help narrow options, sway decisions, and enable quick choices, often without conscious awareness. These markers shape decisions even before we consciously think about them. 

Every experience leaves a physical trace, not a memory in the usual sense, because it can’t be retrieved and described like other memories, but a bodily residue: a tension, an unease, a quickening, a settling. 

These traces accumulate over a lifetime. When we face a new decision, the body reacts, registers similarities to situations that went well or badly, and signals, before conscious thought has begun, something about the options before us.

This is what it means to sense that something feels right, off, or just not quite sitting well with us. We're not just imagining it. Instead, we're picking up on the body's memory of a pattern it has recognised, a pattern stored through experience, not in words, but in sensations that our body remembers.

Instinct might seem like the perfect word for this, as it captures how knowledge often comes to us as a feeling rather than through logical arguments. It feels instinctive, something we sense rather than think through. But calling it instinct can be misleading, because true instinct is innate, and this isn’t. Instead, somatic markers are shaped by our experiences, which is why a teenager’s gut feeling can differ greatly from that of a parent with decades of life experience. What we often call a "gut feeling" might be the wisdom we've accumulated over a lifetime.

Somatic markers aren't perfect. They can be influenced by bias and past trauma, just as they can hold valuable wisdom. Damasio's key message isn't that intuition is always right, but that without it, even the most sophisticated reasoning can fall short, as shown in Elliot’s case.

Our way of living, with instant access to information and a focus on logical planning, evaluation, and optimisation, might have made us less willing to trust our gut feelings. Today's work is mostly mental and involves sitting for long periods. We read, communicate, scroll, and analyse in positions that slowly distance us from our physical sensations. 

Walking or running, especially on uneven and unpredictable terrain, offers effects that few other activities can match. It stimulates the body's sensory systems: proprioception kicks in with each step on rough ground, the vestibular system constantly adjusts for balance, and interoceptive awareness is amplified through prolonged physical activity. Navigating challenging terrain transforms the body into a more responsive and sensitive instrument.

At the same time, the analytical mind relaxes its usual control. It focuses on navigation, slope, surface, and footing without being overwhelmed by data. The normally overloaded mind, which typically drowns out bodily signals, assumes a more balanced role. This allows more time to attend to the body's messages. 

A walker who returns from a long trail with clarity they didn't expect has not had a revelation. They have encountered better conditions for receiving what was already present.

Big thinkers have always recognised this and intentionally incorporated it into their daily lives. Kierkegaard enjoyed strolling through the streets of Copenhagen for hours each day. Rousseau, who preferred to walk everywhere, believed his mind functioned best when outdoors. Darwin created a special 'thinking path' at Down House, where he would walk and ponder as part of his daily routine. 

Sometimes, the most important insights come not from argument or adding more information, but through the body, when there is enough movement and silence to let it speak. 

Walking is not a wellness practice or a break from thinking. It is a means of building an archive of bodily experience, a way to quiet our overly rational selves, and an opportunity to think differently. 

Going with your gut remains an important part of decision-making. It must be practised through experience and listened to by creating conditions that are quiet enough and physical enough to hear it.