Carefully prepared under the auspices of the British Academy's Medieval Texts Committee, this is a most useful and reliable book. Volume two in a series, it covers medieval Latin Aristotelian commentaries preserved in Cambridge libraries, volume 1 having covered Oxford libraries. Its incipits were checked for accuracy not once but twice by Cecilia Trifogli (9). Readers will be happy to learn that "Aristotelian" is broadly construed, so that commentaries on the works of Porphyry and Boethius, for example, are also included.
The format and the conventions employed in the catalog are clearly described in the introduction. Valuable for example is the warning that incipits are provided only for commentaries, and this is one minor shortcoming of the volume. In some cases it would have been entirely feasible and very useful to give the incipits for glosses--case in point, Gonville & Caius MS 494/263 reproduced on the frontispiece. On the other hand, the book would have grown beyond control had its editor Rodney Thomson tried to reproduce incipits for all of the Aristotle texts themselves.
Speaking of its editor, Rodney Thomson is a very experienced and helpful cataloguer. He tells us, for example, which script nomenclature system he is using: T. J. Brown, as presented in Michelle Brown's Guide to Western Historical Scripts. This will serve as a warning to those like myself who are accustomed to employ instead the nomenclature used in Albert Derolez's Paleography of Gothic Manuscript Books. A similarly valuable warning is Thomson's reminder that the Aristotle texts encountered in these manuscripts, particularly those used in lemmata, are likely to vary quite a bit from the texts published in Aristoteles Latinus (19). Thomson also tells us which two libraries preserve the greatest number of such manuscripts: the college libraries of Peterhouse and Gonville & Caius. In the case of Peterhouse, Thomson did two things that will also be valuable: first, he catalogued the pastedowns (16), and second, where needed he provided modern foliation in the manuscripts of Gonville & Caius and Peterhouse themselves (24), together with a warning that this means that the current correct foliation may differ from that provided in earlier reference works.
For those seeking to reunite scattered folios, Thomson continues the valuable practice of indicating the size of the written space as well as the size at which book binders have left them. He also gives the opening words of the second folio which will be useful if these manuscript again have their first folio removed. Speaking of depredations, Thomson notes the sad fact that somebody or bodies has removed all the major decorations from the Peterhouse manuscripts (20).
Myself, I find it interesting just to read through the catalog thinking about which of the anonymous or little known works would repay further study. What should one make of what is described as a Meteorology commentary by Roger Bacon? For others, it may be valuable as a sort of prosopographical aid, since Thomson has spent a lot of time listing the names of owners and authors as a supplement to the information available in Emden's Biographical Registers.
Oddly, both at Oxford and at Cambridge, William Ockham's enemy Walter Burley is the commentator whose works are best represented (16). Having spent some time with the Doctor planus, I found his work boring when he wasn't insulting Ockham--as, for example, as a beginner in logic. So much for the "Venerable" in "Venerable Inceptor." And I note with regret that Thomson didn't consult the work of Wood and Ottman, and hence a reader can't tell which edition of Burley's Physics commentary is preserved where. Thomson does, however, provide thorough and systematic reference to the more standard authorities, such as Lohr, Sharpe, Weijers, and Zimmermann, which will save further researchers considerable time.
Finally, the volume closes with some nice color reproductions and ample indices. Thomson has included reproductions illustrating the standard layout of glosses and commentaries, and also what may be a manuscript with marginal notes written by Albert the Great himself. Other reproductions seem to reflect a whimsical sense of humor. The reader will find an illustration of a dog attending to genital hygiene and a note suggesting that a section of Burley's commentary on Aristotle's Generation and Corruption is worthless: rubarbe. So even readers not excited by seeing a thirteenth-century commentary on Boethius' De divisione may find the volume interesting.