One evening a couple of years ago, with some cicadas making a deceptively comfortable racket outdoors, and the mountains easing from green to blue to purple, I sat down alone at a desk full of papers and photographs and notebooks and articles torn out of magazines and loose paper clips and Bic pen tops and empty film cans and general trash like that; and I shoved it all around and got enough flat space to make an introduction to a book some high school kids and I had put together.