One of the stars of the Oriental Institute's new show, "Visible Language: Inventions of Writing in the Ancient Middle East and Beyond," is a clay tablet that dates from around 3200 B.C. On it, written in cuneiform, the script language of ancient Sumer in Mesopotamia, is a list of professions, described in small, repetitive impressed characters that look more like wedge-shape footprints than what we recognize as writing. In fact "it is among the earliest examples of writings that we know of so far," according to the institute's director, Gil J. Stein, and it provides insights into the life of...