I bought the above whiteboard yesterday for tomorrow’s talk. When I used a flip chart for the talk I drew diagrams then at strategic points I turned over the page and was faced suddenly with an entirely blank sheet: a complete change of subject. With a whiteboard I can erase my images incrementally as I continue to speak, so the subject can’t change suddenly, and elements of each image can be isolated and newly associated with other things. I think this will do some good. I’m also interested to see how I can make the surface of the whiteboard refer to the Borgesian ‘operating table’:

“the table where, for an instant, perhaps forever, the umbrella encounters the sewing-machine; and also a table, a tabula, that enables thought to operate upon the entities of our world, to put them in order, to divide them into classes, to group them according to names that designate their similarities and their differences – the table upon which, since the beginning of time, language has intersected space.”
(M.  Foucault, The Order of Things, Routledge 1989 p. xix)