Originally, “idea” meant the way something looks. This is still true for most people—I suppose it is true for artists in a special sense. During the later Renaissance, when the connection between ideas as images and ideas as thoughts was very conscious, good illustrations began to appear in serious books. Phrases like “This image demonstrates…” became common. The woodcuts in Vesalius’ books of anatomy are the most beautiful and significant examples; I consider them in my thesis. At the entrance to the anatomical theatre in Padua where he worked was written: “Here is the place where death delights to help the living.”