In the popular imagination, philosophy is done “from the armchair.” It’s an image that suggests both comfort and detachment, and that makes philosophizing the preserve of those with sufficient time and repose to isolate themselves from the world and follow their intuitions. 

Yet not all philosophers have been happy to stay seated. The empirical orientation of Aristotle’s school in ancient Athens was symbolized in the members’ nickname—“the Peripatetics”—a label they acquired from their habit of walking while discussing philosophical ideas. Hippocrates, also a physician, proclaimed that “walking is man’s best medicine.” Kant is known to have taken walks every day (with such an intense regularity that the housewives of Königsberg are said to have told time by them). 

Meanwhile Nietzsche, whose mature works were the product of an itinerant lifestyle spent mostly in cheap Italian hotels, once advised, “Sit as little as possible; do not believe any idea that was not born in the open air and of free movement—in which the muscles do not also revel. All prejudices emanate from the bowels.” Here we have one of the fiercest condemnations of the armchair imaginable: In Nietzsche’s image, the idle posture of the proverbial “armchair philosopher” is quite literally allowing feces to rise to their brains.

But why should we think better thoughts when we are walking rather than seated? The armchair philosopher is isolated but so too is the lone wanderer, hiking in the hills above the clouds. Surely, it matters where we walk—and with whom. The armchair philosopher is comfortable, and so might fall prey to delusion, but this can be equally true of the philosopher whose ideas are formed while strolling with colleagues round an Oxford quad.