Whenever you look at yourself in a mirror, you are looking at one of the miracles of the world. Behind the eyes, the mouth, the ears, the nose, and the skin, all of which bring information to your brain, lies the brain itself- a magnificent computer, far more complex and skillful than any computer ever built. Stored within your brain-computer is a great wealth of perceptions, ideas, and memories that have come to you through years of experience. In an instant you can select the information you need. Animals also have computers inside their heads. They can remember to some extent, and sometimes they appear to guess what will happen next in order to get ready for it. Nearly all animals can make noises by which they might communicate with one another, perhaps about danger or food or some very simple desire. Some animals can be trained to react to commands spoken by humans, and a few can even be taught to make "human" sounds. But human beings alone among the mem...