According to Isidore of Seville, a seventh-century Spanish bishop, there are three things associated with each letter of the alphabet: nōmen, figū́ra, and potéstās.2 Isidore explained that a letter’s nōmen, “name,” refers to how it is called; a letter’s figū́ra, “shape,” to how it is formed; and a letter’s potéstās, “meaning,” to how it is signified. Take the first letter of the Latin alphabet, for example. Its nōmen is “a,” its figū́ra is its particular shape, and its potéstās