Why do you think Michelangelo chose to sculpt his Moses (2.4.8) from marble, or Marcel Duchamp decided to appropriate a urinal (3.10.1) in order to declare it a work of art? Look carefully at the materials used by the artists and their unique qualities—the durability of stone, the shininess of the ceramic glaze—and try to see what associations the artist may have had in mind when they chose the material or process. Would Michelangelo’s work be as effective were it made from clay? How would that change the work?