I was delighted to see Dominic Sayers' encomium for Edward Tufte on Confused of Calcutta, so I would like to use that opportunity to take things to the next level. I would like to argue that Tufte’s impact goes far deeper than visual literacy. Using Newton Garver’s Preface to a collection of essays by Jacques Derrida as a point of departure, I would claim that Tufte is addressing an issue that goes all the way back to the scholastic trivium of grammar, logic, and rhetoric. Our modernist thinking has made great strides in our command of grammar and logic, but it seems to have done so at the expense of our appreciation for rhetoric. Tufte’s appreciation for rhetoric is particularly evident in an interview he gave to Mark Zachry and Charlotte Thralls in which he discussed his book Beautiful Evidence. Furthermore, when we consider the full title of Visual Explanations: Images and Quantities, Evidence and Narrative, we see that Tufte has a keen intuition for the literary theory of text types. This has nothing to do with how fonts are designed and used. Rather, it is an effort to classify texts (in the most general sense of the term) into the categories of argumentation, description, exposition, and narrative. Tufte’s recent concern with evidence addresses how his concerns with design impact argumentation, while Envisioning Information makes solid contributions to both description and exposition. I believe that Visual Explanations was his first serious effort in the area of narrative, although he was already addressing narrative in The Visual Display of Quantitative Information.
The point I am trying to make from my own reading of Tufte is that it is not only visual literacy that is at stake. Rather, it is the full scope of literacy, where rhetoric is as important as grammar and logic and where that rhetoric is exhibited in the text types of argumentation, description, exposition, and narrative, whether the “texts” are traditional documents or PowerPoint presentations. As a matter of fact, rhetoric also comes into play in the conversations we hold; so I believe that we can invoke Tufte when we deal with questions of literacy of “real-time” texts.