" the mind is not sealed in the skull but extends throughout the body. We think not only with our brain but also with our eyes and ears, nose and mouth, limbs and torso. And when we use tools to extend our grasp, we think with them as well. “Thinking, or knowledge-getting, is far from being the armchair thing it is often supposed to be,” wrote the American philosopher and social reformer John Dewey in 1916. “Hands and feet, apparatus and appliances of all kinds are as much a part of it as changes in the brain.”51 To act is to think, and to think is to act. "

― Nicholas Carr , The Glass Cage: How Our Computers Are Changing Us