We all have bodies, and all our bodies function in much the same way.
Each of us originates in a fertilized egg; we all breathe and maintain a
heartbeat; we all eat, digest, and excrete. If we cannot perform these
basic functions for ourselves, then our life depends on medical
machinery doing them for us. In these respects we are all alike, and
like, too, not only all the generations of human beings before us, but
all mammals, birds, and reptiles. Bodies, you could say, have no history
because they have been much the same since the first human beings
came into existence....