The Insistence of the Letter in the Unconscious, or Reason Since Freud

The introduction is devoted to situating the text as lying midway "between writing and speech".

Thus, if the idea is that “Instance of the Letter” is as much like a talk as it is like a paper, the talk itself was more like the public reading of a written paper than most of Lacan's other talks: The talk would seem to have been mostly written out in advance.