“The theory has been advanced that the modern signature is, pradoxically, a product of illiteracy. The signs and signatures that came into use during the thirteenth century are only letters and signs grafted onto crosses. Kings, as well as their lowest subjects labored on their monogrammed crosses, and few could probably read what they signed.”

—Bernard Rudofsky, from Seven Designers Look at Trademark Design, edited by Egbert Jacobson, 1952.