The Extended Mind: The Power of Thinking Outside the Brain

by Annie Murphy Paul

Remember Friedrich Nietzsche, from earlier in our journey. “Only thoughts which come from walking have any value,” he maintained. Søren Kierkegaard felt similarly. “I have walked myself into my best thoughts,” remarked the Danish philosopher. Walking is “gymnastics for the mind,” observed the American writer Ralph Waldo Emerson. “I am unable to reflect when I am not walking; the moment I stop, I think no more, and as soon as I am again in motion, my head resumes its workings,” averred the Swiss-born philosopher Jean-Jacques Rousseau. The French philosopher and essayist Michel de Montaigne lamented that his thoughts often came to him when he was on the move, at moments when “I have nothing to jot them down on”; this was wont to happen “especially on my horse, the seat of my widest musings.”