Digital technologies have reshaped the communicative environment, making readily available the ability to integrate images and words in compositions. However, strategies to invent images lag far behind our technological capabilities. This dissertation works to understand inventional practices for images through a historic perspective. It explores the invention of images and decoration for the creation of meaning in the Book of Kells, a ninth-century illuminated manuscript made by Irish monks on the small island of Iona, just off the western coast of modern day Scotland. The Book of Kells is considered by scholars to represent the flowering of illuminated manuscripts made in the British Isles.

Invention has long been a central aspect of rhetorical theory. However, scholars of rhetoric focus on invention as it relates to generating words, and scholars of visual rhetoric tend to be more interested in analyzing visuals rather than generating them. This dissertation responds to the need for research and scholarship in the invention of images. The first part of the dissertation traces the waxing and waning cycles of the use of visuals for thought and communication in literate practices. It establishes the image's significance for thought in ancient times, drawing attention to Aristotle's belief that thinking is impossible without the image. It supports Aristotle's position by establishing the images essential role for memory and invention in classical rhetorical treatises by Cicero, Quintilian, and the author of the Ad Herennium. However, the image's role in classical times was to generate words; therefore, the dissertation follows the changes that occurred in the Middle Ages when the goal of invention shifted to producing images for religious practices. In the second part, the dissertation presents recovered inventional strategies used by the monks of Iona for the making of the Book of Kells. These practices include techniques for visualization and meditation. It proposes a way to theorize the image as an object of thought using Charles Sander Peirce's work in semiotics and describes methods that can be applied to integrate images into compositions. This study demonstrates the value in recovering further inventional practices from other periods when images flourished.