According to a much-repeated story, Immanuel Kant took his afternoon walk through Königsberg with such punctuality that his neighbours could set their clocks by him. Whether or not that is literally true, the daily walk was a fixed point in one of the most rigorous intellectual lives ever lived. He was hardly alone. The followers of Aristotle were known as Peripatetics, a name traditionally linked to the covered walkway where their master taught. Philosophy, it seems, has always had something to do with the feet.
Søren Kierkegaard, who spent hours each day wandering the streets of Copenhagen and talking to whoever he met, put it most memorably in a letter to a young relative. Above all, he advised her, do not lose the desire to walk. He claimed he had walked himself into his best thoughts, and that he knew of no thought so burdensome that one could not walk away from it. It is advice from a man not otherwise known for his cheerfulness, which makes it all the more persuasive.
Friedrich Nietzsche was blunter still. He composed much of his work during long walks in the Swiss Alps and along the Ligurian coast, and he insisted that only thoughts reached by walking had any value. Jean-Jacques Rousseau, in his final, unfinished book, Reveries of a Solitary Walker, arranged his reflections as a series of walks. For these writers, walking was not a break from thinking. It was where thinking actually happened, in rhythm with the body and the passing world.
Thinking at walking pace
Why might this be? One plausible answer is that walking occupies the body just enough to quieten a certain kind of anxious self-monitoring, while leaving the mind free to drift. The pace matters. At walking speed, the world changes slowly enough to be noticed but quickly enough to keep offering something new: a doorway, a stranger's face, a change in the light. Thought moves associatively, following these prompts, and connections form that would never appear while staring at a screen.
The city adds another dimension. The nineteenth-century figure of the flâneur, celebrated by Baudelaire, was a walker who drifted through Paris observing rather than hurrying, reading the street like a text. To walk in a city is to be continually reminded that other lives are unfolding alongside your own. It is a quietly moral experience. The walker cannot avoid the man sleeping in the doorway, the elderly couple crossing slowly, the child staring from a bus. Cars and headphones make such encounters easier to ignore.
Modern life has made walking optional for many of us, and in doing so may have removed one of our oldest tools for thought. We commute sealed in vehicles, move between rooms rather than streets and fill every stroll with podcasts. None of this is sinful. But it may explain why so many people report that their best ideas arrive in the shower, one of the few remaining places where the mind is allowed to wander unaccompanied.
The remedy is almost insultingly simple. Walk somewhere without a destination at least once a week, for an hour, without headphones. Take a problem with you and do not try to solve it. Let the streets or fields do some of the work. Kierkegaard, Nietzsche and Rousseau disagreed about nearly everything, but on this they were united. When thinking gets stuck, the answer is often not to sit harder, but to get up and go out.
