“When you look in the mirror you see not just your face but a museum. Although your face, in one sense, is your own, it is composed of a collage of features you have inherited from your parents, grandparents, great-grandparents, and so on. The lips and eyes that either bother or please you are not yours alone but are also features of your ancestors, long dead perhaps as individuals but still very much alive as fragments in you. Even complex qualities such as your sense of balance, musical abilities, shyness in crowds, or susceptibility to sickness have been lived before. We carry the past around with us all the time, and not just in our bodies. It lives also in our customs, including the way we speak. The past is a set of invisible lenses we wear constantly, and through these we perceive the world and the world perceives us. We stand always on the shoulders of our ancestors, whether or not we look down to acknowledge them.”