The Extended Mind: The Power of Thinking Outside the Brain

by Annie Murphy Paul

Thinkers have long mused on how it is that we can regard ourselves as unique and persistently existing entities. “What makes me the same person throughout my life, and a different person from you?” wondered the late philosopher Derek Parfit. Their answers have usually had something to do with the brain—with our thoughts or our memories. As the French philosopher René Descartes declared, “I think, therefore I am.” According to neuroanatomist and interoception expert A. D. Craig, it would be more accurate to say, “I feel, therefore I am.” Craig maintains that interoceptive awareness is the basis of the “material me,” the source of our most fundamental knowledge of ourselves. Because our hearts beat, because our lungs expand, because our muscles stretch and our organs rumble—and because all these sensations, unique to us, have carried on without interruption since the day of our birth—we know what it is to be one continuous self, to be ourselves and no other. Interoception, says Craig, is nothing less than “the feeling of being alive.”