At least up until 1508, for Leonardo, macrocosm and microcosm were closely bound together. Among his books on the cosmos and the world we find the Sphere by John of Holywood, and Ptolemy’s Cosmography. This macrocosmic research was directly linked to his study of the microcosm: the human body, the “lesser world” about which Leonardo planned to create an anatomical atlas, with plates similar to those in Ptolemy’s book on the cosmos.