 Things really get complicated when we come to Scotus’s commentaries on the four books of Sentences of Peter Lombard, since he commented on the Sentences more than once and revised his lectures over a long period; the relations among the various versions that have come down to us are not always clear. Certainly the Lectura presents us with Scotus’s Oxford lectures on Books I and II of the Sentences in 1298–99. There is an Ordinatio (i.e., a version prepared for publication by the author himself) of lectures at Oxford, based in part on the Lectura and on material from his lectures in Paris. The Ordinatio, which Scotus seems to have been revising up to his death, is generally taken to be Scotus’s premier work; the critical edition was at last completed in 2013. Finally, Scotus lectured on the Sentences at Paris, and there are various Reportationes of these lectures. A critical edition is in progress; at present we have a transcription of a reasonably reliable manuscript of Book I. Although the Paris lectures themselves were later than the Oxford lectures, it seems probable that parts of the Ordinatio—Book IV and perhaps also Book III—are later than the corresponding parts of the Reportatio.