All truly great thoughts are conceived while walking, observed Nietzsche, though I’ve always been a bit suspicious of the eagerness with which writers and artists celebrate the inspirational power of taking a stroll. Yet it seems to work. "methinks(我想) the moment my legs begin to move, my thoughts begin to flow," was how Henry Thoreau described an experience many of us have had, be it tackling challenging work or worrying over problems. If we still don’t know why walking inspires clarity and creativity, it’s because there are too many possible explanations, not too few. An evolutionary psychologist might say we’re designed to thrive outside, not at a desk; a scholar of the psychological phenomenon of "priming" might point to studies suggesting that high ceilings-and also, perhaps, the sky—prompt unrestrained thinking. A study in the European Journal of Developmental Psychology offers more straightforward reasoning. In it, both children and s performed a memory exercise better when walking than sitting. The researchers speculate that the physiological inspiration of walking simply makes for better brain functioning, while the normally harmful effects of multitasking are eliminated when the tasks are sufficiently different, drawing on separate "wells" of attention, rather than fighting over one. Maybe. Going solely on anecdotal(趣闻轶事) experience, though, I suspect the greatest mental benefits of walking are explained not by what it is, but by what it isn’t. When you go outside, you cease what you’re doing, and stopping trying to achieve something is often key to achieving it. Stepping away from work combats the paralysing effects of perfectionism, because when a task is suspended, the risk of failure is suspended, too; you’re thus freer to dream up insights. And in some hard-to-specify way, even the distractions of walking— traffic noise, people—seem to help. The writer Ron Rosenbaum takes this to extremes, not just walking while thinking, but watching TV while writing. "I’m slightly ashamed to admit it, since it sounds like such an exceedingly bad violation of the writer’s solitude," he once said. "But I have a theory of ’competing concentration’... if you have something that you have to focus against—it forces you to concentrate. " Naturally, the self-improvement industry has ideas to optimize (充分利用) your inspirational walking—the notebook will capture your breakthroughs. I’m more sceptical of the merits of a desk for home treadmills. But all you really need do is go for a walk. "I only went out for a walk and finally concluded to stay out till sundown," the naturalist John Muir wrote, "for going out, I found, was really going in." Deep. Though apparently he never had to worry about deadlines.

As for Nietzsche’s opinion of thought and walk, the author holds that ______.