by Amanda Gerber
In her most recent post on Listology.blog, Martha Rust introduced us to distinctiones, or diagrammatic arrangements of lists into visual shapes, which could then be reconstituted in different arrays for sermons. This post returns to this issue of the diagrammatic list to explore two central questions: Where does one draw the line between list and diagram? Or should a line even be drawn? And does a diagram’s formatting change how a reader conceptualizes or acts upon its itemized information? To begin addressing these questions, I turn to a fourteenth-century manuscript copy of Lucan’s Pharsalia (a Latin epic about the civil war between Julius Caesar and Pompey the Great at the end of the Triumverate in the first century BCE) in Oxford, Bodleian Library, MS Canon. Class. Lat. 70. The manuscript itself is brimming with diagrams covering mostly geographical subjects, but thrust among its diagrams and extensive notes is a hybrid of paratexts (that is, notes or diagrams) about the planets, one which cannot seem to determine whether it wants to be a diagram or a list.
The paratext appears in reference to the beginning of Book 10 of the Pharsalia, a beginning that, in epic fashion, elaborately notes a change in time by mentioning the celestial movements that differentiate day from night, among other things. One medieval annotator takes this poetic convention as an invitation to pronounce his own celestial knowledge, which he recites in a list about what exists in the firmament above (“fi[r]mam[en]tum sup[er]ius e[st]”). The annotator then supplies the following list:
In celo Io Satu[r]nus
In celo IIo Iuppiter
In celo IIIo Mercurius
In celo IIIIo Sol
In celo Vo Venus
In celo VI Mars
In celo VII Luna (f. 132r)
[In the first heaven Saturn / In the second heaven Jupiter / In the third heaven Mercury / In the fourth heaven the sun / In the fifth heaven Venus / In heaven six Mars / In heaven seven the moon]
The list sits atop a collection of concentric circles, a diagrammatic format derived from Aristotle and used throughout the Middle Ages to represent the planetary spheres. In this diagrammatic tradition, each circle depicted a particular planet’s geocentric rotation. The annotator seems to have added the diagram to the manuscript before its accompanying planetary list, a sequencing supported by the fact that the bottom of the list supplies two bracketing lines with the first attaching to the syllables “ce” to the left of the diagram and “li” to the right—which combine to say “celi” or “heavens.” In other words, at some point soon after drawing the iconic concentric spheres of the heavens, the annotator determined it insufficient for encapsulating the firmament’s planetary line-up. But rather than supply the words within the image, the paratext presents the list and diagram as two separate but related explanations of the cosmos.
The order in which these planetary paratexts were inserted renders the list an explication of the diagram rather than the diagram a clarification of the list. As opposed to modern assumptions about the predominance of the visual, this Latin learner (or educator) treats the visual as a message that needs clarification. Ildar Garipzanov expounds on this distinction between medieval visual and verbal learners in her recent work on “graphicacy,” a term that refers to the skill required to read graphs. According to Garipzanov, graphicacy requires “the visual-spatial ability of intelligence,” a form of intelligence that must be studied just like any other form of literacy. My own findings largely corroborate Garipzanov’s: even for classical poems, a corpus with which medieval readers required copious assistance, annotators tended to prefer discursive notes and lists to more graphic aids. In the case of this particular Lucan annotator, the list serves to train the audience in how to read the visual image, marking the list as the more self-evident form of textual explication. Therefore, in returning to this post’s opening questions about the distinctions between lists and diagrams, the Lucan annotator appears to consider them interrelated yet separate forms of explication. In his case, he had to train his manuscript’s users how to read a list between its diagrammatic lines.
 By the time Canon. Class. Lat. 70 was produced, other representational formats were circulating throughout Europe, formats that helped account for seeming planetary irregularities from a geocentric perspective. The concentric model, nevertheless, continued to circulate throughout the Middle Ages. For more about planetary diagrams, see especially Bruce Eastwood and Gerd Graßhoff, Planetary Diagrams for Roman Astronomy in Medieval Europe, ca. 800–1500 (Philadelphia: American Philosophical Society, 2004).
 Ildar Garipzanov, “The Rise of Graphicacy in Late Antiquity and the Early Middle Ages,” Viator: Medieval and Renaissance Studies 46.2 (2015): 1-17, especially 16-17.
 Ibid., 16-17.