The only complete Medieval Latin text of the Metaphysics has been composed by William of Moerbeke, partly as a revision of the Translatio Media (books I-X and XII-XIII.2) and partly as an original translation (books XI and XIII.2-XIV). In both parts of the text, the editor has revealed the existence of two chronologically distinct versions. As in the edition of the De generatione animalium, the variant readings of the earlier version are displayed in the critical apparatus.
The preface to the edition covers the entire first volume of the publication: it clears up the intricate situation of the manuscript tradition, describes the translation process and method, and discusses the translator's Greek copies of (and other information on) Aristotle's text. It should be mentioned, in particular, that the present-day manuscript Vindobonensis gr. 100 has been identified as one of Moerbeke's Greek models for his translation of the Metaphysics.