Book I survives in an ''ordinatio'' or revised and corrected version, approved by the author himself for publication. Books II-IV survive only as a ''reportatio'' a transcript of lectures, taken down by a 'reporter', without the benefit of later revisions or corrections by the author. | Book I survives in an ''ordinatio'' or revised and corrected version, approved by the author himself for publication. Books II-IV survive only as a ''reportatio'' a transcript of lectures, taken down by a 'reporter', without the benefit of later revisions or corrections by the author. |