  These works vary in size from a couple of pages to over a hundred. They seem to be occasional writings in the sense that they constitute written responses by Plotinus to questions and problems raised in his regular seminars.  Sometimes these questions and problems guide the entire discussion, so that it is sometimes difficult to tell when Plotinus is writing in his own voice or expressing the views of someone else.  Typically, Plotinus would at his seminars have read out passages from Platonic or Aristotelian commentators, it being assumed that the members of the seminar were already familiar with the primary texts.  Then a discussion of the text along with the problems it raised occurred.