As an artist and teacher, John was interested in understanding the structure of things around him. He would draw with great care and patience to present this understanding to viewers of his drawings, as well as to his students, how and why something has the appearance that it does, whether it is large or small. He had a naturalist’s eye for the differences between things that might at first appear the same. So he would draw a tree, a cow’s skull or a mountain with the same intention of showing each one’s particular nature.