In the famous Egyptian painting known as the Papyrus of Ani, made around 1250 BCE and now in the British Museum, a scribe and his wife stand in a hall of judgment. In the center is a great pair of scales. On one side lies a small vase, which holds the scribe's heart. On the other side sits a single feather. A jackal-headed god adjusts the balance, an ibis-headed god waits with a writing palette, and beside him crouches a creature with the head of a crocodile and the body of a lion and a hippopotamus. This is the weighing of the heart, one of the best-known images of ancient Egypt. To understand why the heart, and not any other organ, sits on the scale, one must see how the Egyptians understood the body and the mind. The Heart as Mind The Egyptians had a word for the heart, ib , and another, haty , for the chest area or the organ itself. To them, the heart was the seat of thought, will, memory and feeling. When we say "I think" or "I remember," the Egyptian...