Great Minds

Do great minds think alike? Here a couple of striking quotes separated by a millennium and a half. First of all comes Cassiodorus, who seems to have had quite definite ideas about how to employ diagrams:
Duplex quodammodo discendi genus est, quando et linealis descriptio imbuit diligenter aspectum, et post aurium praeparatus intrat auditus. (Institutions 2, praef. 5. Possible translation: Learning is a dual process: the visual mind first acquires the exact context through a drawn figure, so that an attuned aural perception can grasp the subsequent discourse.)
Here are Christopher Chabris and Stephen Kosslyn in 2005:
To be maximally effective, the diagram should be examined before the reader encounters the relevant text, in part because the diagram helps to organize the text, and in part because the reader may try to visualize what the text is describing and the results may not match the diagram.
There is a more thorough discussion of Cassiodorus on my website, including references to Esmeijer's book which first drew attention to this aspect of Cassiodorus's thinking. I have slightly altered the punctuation of Chabris/Kosslyn.

Both passages are onto an important point about thinking through vision: it may not be especially helpful to have access to diagrams after we have discussed topics, but diagrams can be very effective aids, priming the mind to understand things before a more linear form of reasoning commences.
  • Cassiodorus, and R.A.B. Mynors. Cassiodori Senatoris Institutiones. Oxford: Clarendon Press, 1961.
  • Chabris, Christopher, and Stephen M. Kosslyn. “Representational Correspondence as a Basic Principle of Diagram Design.” Knowledge and Information Visualization (2005): 185–186 (Springer).
  • Esmeijer, Anna Catharina. Divina Quaternitas: a Preliminary Study in the Method and Application of Visual Exegesis. Translated by D.A.S. Reid. Assen: Van Gorcum, 1978.