ABSTRACT
When my daughter was three years old, she became quite curious one day about what different things were made of. She ran around the room, excitedly pointing to things, trying to stump me with her questions:
“Daddy, what is the table made of? ” “Wood. ” “Daddy, what is the spoon made of? ” “Metal.” “Daddy, what is this toy made of? ” “Plastic. ” As she looked around for a new object, I turned it around on her, with a ques-
tion of my own. “What are you made of? ” She paused to consider. She looked down at her hands, turning them over, and
studying them. And then, brightly, she announced: “I’m made of skin!” And for a three-year-old, this is a perfectly reasonable conclusion. As we get
older, of course, we learn more about what people are really made of — the complex relations between bones, muscles, organs, and the rest. Even as adults, though, our understanding of human anatomy is incomplete (can you point to your spleen,
for instance? Or describe what it does, or how?), and this is acceptable for most of us, because we generally know enough to get by.
