The commentary map

Every commentary in the Patrologia Latina, grouped by the book it expounds — 239 works across 56 books and groups, 15,537,147 words of Latin, of which 25 now carry an English translation. The map is complete; the translations light it up.

This is a different question from the scripture index, which records every verse Migne's authors quote, located by column. Here a work appears under the book it is about. Membership is derived from each work's title as Migne prints it and then corrected by hand, so it is a good guide and not an authority: a commentary whose title names no book is missing until someone adds it. Works that expound a whole collection — the Pauline epistles, the four gospels, I–IV Regum — keep their own heading and sit at the head of that part of Scripture, just before its first book, rather than being filed under one member they do not confine themselves to.