Contents Home Map

An Aristotle MS bought by W. Voynich from the Jesuits in 1912


The antiquarian book dealer Wilfrid M. Voynich (1865-1930) made an important acquisition of illuminated manuscripts from the Society of Jesus in early 1912 (1). Best known in this context is the manuscript still named after him: the "Voynich MS", now MS 408 of the Beinecke Rare book and MS library of Yale University, New Haven. Other highlights from this collection were sold to the Morgan Library & Museum in New York and several other libraries in the US and Europe (2). While Voynich had been very secretive about this collection of manuscripts, we now know that they originate from the Bibliotheca Major of the Collegium Romanum.

The origin of this collection is confirmed among other things by archival material preserved in the Beinecke library. Many of the manuscripts had paper slips attached to their inside front cover, with descriptive information about the manuscript. Voynich removed these in order to leave no traces of the origin of these manuscripts, in line with his promise of secrecy about the sale. One of 16 such slips, still preserved in the Beinecke library, refers to a Latin Aristotle manuscript comprising 10 books. It is shown in the Figure below (click on the image for an enlargement).

The small paper attachment to this slip: "ex Bibliotheca privata P.Petri Beckx" (partly obliterated) refers to the time that the posessions of the Society of Jesus were confiscated in 1873. Petrus Beckx S.J., Superior General of the Jesuits, was allowed to retain his private library, and this was apparently stocked up with some of the most valuable items from the Jesuit libraries. This collection was thereafter moved into a safe hiding place to avoid confiscation.

By 1912, the Jesuits decided to sell a small part of these books to cover financial needs (3). They drafted a handwritten catalogue of these books for sale, of which the original is now preserved as "APUG 3289" in the historical archives of the Pontifical Gregorian University in Rome, while a photographic copy is preserved in the Vatican Library (4). This is a list of printed books and manuscripts sold to the Vatican, although some of the manuscripts were in reality not sold to the Vatican Library, but to Wilfrid Voynich (5). There are later annotations in the margins of this list with present Vatican shelf marks (Vat.Lat. 11414 - 11709), or other remarks in case the volume was sold to Voynich. These annotations were made by Mgr. José Ruysschaert (6), vice-prefect of the Vatican library, when he was preparing his catalogue of the Latin manuscripts obtained from the Jesuits on this occasion (7).

More about the Aristotle manuscript

The Aristotle MS that is discussed in this page was acquired by Voynich, as demonstrated by the fact that this bibliographical slip was preserved among his papers that are now at the Beinecke Library. Looking at the Figure above, there are further annotations in pencil on this bibliographical slip. The entry near the bottom left says "N100", and is most probably an entry from Wilfrid Voynich himself, with an early inventory number (8). The other pencilled remarks in the top margin are in the hand of Miss Anne M. Nill (9), where she indicates that this manuscript was later sold to the Huntington Library in San Marino, California, making reference to De Ricci (10) p.82, where an Aristotle MS appears with shelf mark HM 1035.

In the introduction to Ruysschaert's voluminous printed catalogue, he presents a list of manuscripts that were probably acquired by Voynich (11). Ruysschaert, too, makes reference to De Ricci (1937), and he includes two other manuscripts sold through Voynich to the Huntington Library, but he omits this one (12). The reason for this omission is almost certainly that this MS does not seem to appear in the handwritten catalogue of the Jesuits that was described above. However, we will come back to this point further below. The annotation by Anne Nill on the slip also includes a question mark, undoubtedly because the Huntington manuscript only consists of 98 folios comprising books 8-10 of the original manuscript. Before searching for the remaining books, it is worth looking at this manuscript in more detail.

The library of Pierleone Leoni of Spoleto

The Huntington library has published a guide to its medieval and renaissance manuscripts (13), which we may refer to in the following as the "Huntington guide". The description of HM 1035 in this guide identifies it as a manuscript that was once in the library of Pier Leoni, physician of Lorenzo de Medici:

Belonged to Pier Leoni (d. 1492), physician to Lorenzo de' Medici. The inventory of Leoni's books was published in L. Dorez, "Recherches sur la bibliothèque [...] where this manuscript may be identified with item 8, "Aristoteles de natura animalium." (14)

The Huntington guide entry also refers to a study of Leoni's library by Ruysschaert (1960) (15), but also here this Aristotle MS in the Huntington library appears to have been unknown to Ruysschaert. He does include Huntington HM 65 in this study, which is also a manuscript that used to be in the library of Pier Leoni. From the Huntington guide:

Belonged to Pier Leoni (d. 1492), physician to Lorenzo de' Medici; n. 111 in the inventory of his books compiled in 1582 and published by L. Dorez, "Recherches sur la bibliothèque [...] . Identified by J. Ruysschaert, "Nouvelles recherches [...]. Probably belonged to the Jesuit College in Rome, some of whose books passed to the Vatican Library in 1912. At the same time approximately 27 of their manuscripts were sold to the bookdealer W.Voynich, including HM 65.

According to Ruysschaert (1960), the Pier Leoni manuscripts may be identified by two common properties:

  1. The cover with author and title in Gothic writing on the dorso and a numeral at the top
  2. Numerous glosses in Leoni's hand

The Huntington guide confirms that the binding of HM 1035 is the same as that of HM 65, and the latter can be viewed online (16). Examples of this type of binding may be observed in the Vatican digital collections (17). There are additional illustrations of these volumes in Ruysschaert (1960), showing several examples of this binding style. The cover of the Aristotle MS furthermore appears to be the cover for the complete set of 10 books, as the Huntington guide entry also explains:

The single title, corresponding to HM 1035 as it stands today, suggests that the book had been bound in its more complete state (cf. the multiple titles on the spine, which must have referred to the text[s] on the missing 130 folios at the beginning of the book), and had been dismembered before 1582, when the inventory of Leoni's library was compiled.

In both entries the Huntington guide refers to the catalogue of Pier Leoni's library composed in 1582, which was published by Dorez (see note 14). HM 1035 was tentatively identified with nr. 8 "Aristoteles de Natura Animalium", and it was pointed out that the original work would have been dismembered prior to 1582. On the other hand, the catalogue slip shown here suggests that this volume was bound together and consisting of 229 folios at a much later date (18). To better understand this apparent contradiction, it is now time to search for the missing part of the complete Aristotle manuscript from the Collegium Romanum.

The missing part of the Aristotle MS

Armed with the bibliographical slip shown above, a search was made in De Ricci's "Census" to see if the remaining part of some 130 folios with 7 books was sold to another American library. This search was successful (19), and in fact it turned out that this part was further divided into two volumes. Consequently, all 10 books of the original manuscript are still available, and they have become separated into three volumes that are now preserved in three different libraries. The following table provides the relevant details:

Books Folios De Ricci Ref. Present location
1 - 5 1 - 66 Vol. I p.700 The University of Illinois, Urbana - Champaign, Rare book and MS library, MS 8
6 - 7 67 - 130 Vol. I p.512, also supplement, pp.151-152 The Newberry Library, Illinois, Ms. 23.1
8 - 10 131 - 228 Vol.1 p.82 The Huntington Library, San Marino, California, Ms. HM 1035

The following table compares the titles of the ten books, as recorded on the slip from the Collegium Romanum, and by the present owners of the manuscripts:

Book Collegium Romanum Present
1 Ethicorum libri X Ethica Nicomachea
2 De bona fortuna De bona fortuna
3 Oeconomicorum libri Oeconomica, libri III
4 Rhetoricum ad Alexandrium Rhetorica ad Alexandrum, libri II
5 Magnorum moralium Magna Moralia, libri II
6 Politicorum Politica
7 Rhetoricorum ad Theodecten Rhetorica
8 De naturis animalium: quod opus transtulit e graeco in latinum Michael Scotus De naturis animalium, libri X
9 De partibus animalium De partibus animalium, libri III
10 De generatione animalium De generatione animalium, libri V

The manuscripts

Beside the concordance of the titles, the three volumes are characterised by a number of similarities, taken from De Ricci and the catalogue entries of the present owners of the manuscripts. These are not conclusive, however, with respect to the question whether manuscripts once used to be together.

The decisive piece of evidence is, that an old foliation consistently runs from 1-229 over the three volumes. Additionally, the third volume has been renumbered in a modern pencil hand. This volume also preserves the common binding, while the other two volumes have a modern limp vellum cover.

Furthermore, according to the Huntington guide, for HM 1035:

On the front pastedown in modern pencil: J991, J992; on f. 1, in modern pencil: 992, a8665a.

Without having seen the J991 and J992 annotations, these appear related to the J1022 written on the inside cover of the "Voynich MS". These annotations on the Aristotle manuscript(s) must have been made at a time when it was already split into two parts. They are modern, and can be associated tentatively with Voynich, who used (among others) H and J catalogue marks before moving to America, and A catalogue marks for his American stock (20). The fact that the number 992 is repeated on the Huntington manuscript suggests that this is the second of the two, at this time. The latter annotation is visible on a digital scan (21), and appears in a similar style as the above-mentioned "J1022".

The annotation "a8665a" on the Huntington manuscript appears to be in a different hand, and MS 8 of the University of Illinois has an almost identical annotation saying "a8665" (22). Taking into account all this evidence, there is no doubt that the complete Aristotle MS was in the hands of Wilfrid Voynich after his 1912 acquisition of Collegium Romanum manuscripts, and he already considered them to be two separate manuscripts, even though they shared a single cover. None of the three manuscripts from the Jesuits that are now in the Huntington library were sold to the library by Voynich himself, but all passed through several hands and no complete trace seems to be possible.

Assuming that books 1-7 used to be a single volume, we may try to identify it in the catalogue of Pier Leoni's library. In the catalogue published by Dorez we find: 132 "Aritotelis Ethica et Œconomica". This should represent the collection of books 1-7, since no item referring to politics or rhetoric is found.

Tentative Conclusion

There seems to be no doubt that the three partial Aristotle manuscripts discussed above all came from the library of Pier Leoni, private physician of Lorenzo de Medici, and were preserved as a single unit in the Jesuit Collegium Romanum library. The following appears to be the history of this manuscript:

Further confirmation of the common past of the three partial Aristotle manuscripts should come from the identification of the glosses that were mentioned above. The identification of the hand of Pier Leoni in these manuscripts would require help from someone with the relevant expertise.

Remaining issue: the oversight of Ruysschaert

The Aristotle manuscript, of which the bibliograhical slip has been preserved, cannot be positively identified in the handwritten catalogue that was the source for Ruysschaert (1959). This is undoubtedly why he omitted it both in this catalogue and in his study of the library of Pier Leoni. On the other hand, the only other two manuscripts that were certainly acquired by Voynich, and which are missing in the handwritten catalogue (24), were correctly identified by Ruysschaert in the footnote to his introduction (see note 11). Of these two manuscripts, the bibliographical slips have not been preserved. It is clear that Ruysschaert has done some research into the list of manuscripts acquired by Voynich during the preparation of his catalogue. How could it happen that he found reference to the other two, of which he should have no prior knowledge, but not the Aristotle. This is all the more surprising as this manuscript would have been of great interest for his study of the library of Pier Leoni published in 1960.

I would like to propose the following hypothesis to explain this. This is that the Aristotle manuscript does appear in APUG 3289, but has been identified incorrectly with an item that was acquired by the Vatican. As a result, Ruysschaert would not be looking for it elsewhere. The item in APUG 3289 says:

Aristoteles | Varia   c. memb. s. inc. | V.L. 11509 [? m] (x

The rightmost part starting with "V.L." is the later identification by Ruysschaert, where the part between brackets was erased but is still partly visible. "Varia" is the summary of the title of the work, and the abbreviation means: "parchment codex of uncertain century". As explained here, these brief entries in APUG 3289 correspond closely with the text on the bibliographical notes. The abbreviation "s[aeculum] inc[ertum]" always corresponds to a case where the century is left blank on these notes, as we see in the Figure near the top of this page.

In Ruysschaert (1959), Vat.Lat. 11509 is described on p.168 as follows (including only the relevant part):

11509. Saec. XIII-XIV, membran., mm. 227 x 160, ff.72, coll. 2, linn. 37.
<S. Thomae Aquinatis, O.P., in Aristotelis posteriorum analyticorum libros I-II expositio>

We may note two mismatches. While Aristotle is mentioned, the author is Thomas Aquinas, whose name should be expected to appear in APUG 3289. The century is given as XIII-XIV, not "uncertain", but this may of course be a later determination by Ruysschaert or another librarian. On the other hand, the single line in APUG 3289 shown above matches with all aspects of the Aristotle manuscript, if we allow that the list of 10 books is just summarised as "Varia".

APUG 3289 does not include any volume by Thomas Aquinas, so presumably the reference to Aristotle was used as the criterium for making the match. It also does not include any other book of Aristotle that could match the bibliographical description discussed on this page. However, this catalogue has numerous 'missing items', that is: manuscripts among Vat.Lat.11414-11707 that cannot be found back in APUG 3289. Our Aristotle manuscript is not at all unique in this respect. In the recent publication by Francesca Potenza (see note 3), many if not most of these cases could be explained, as these missing items are included in another catalogue composed by the Jesuits at the same time, and which is now preserved as APUG 3225 (25).

To verify the above-mentioned hypothesis, the bibliographical slip that should be attached to Vat.Lat.11509 could bring further information, but it turns out that this slip does not exist (26). That the title of the MS in Ruysschaert's catalogue is contained between angular brackets, as shown above, indicates that this is a reconstruction based on the contents of the MS. This means that one of the two manuscripts: the Aristotle now in three US libraries on the one hand, and Vat.Lat.11509 on the other, is not included in APUG 3289. I contend that the brief entry better matches the former, but this cannot be considered certain. An inspection of APUG 3225 could bring more clarity in this matter, but for the time being this is not possible.

Finally, the Huntington library is aware that their manuscript HM 1035 should have appeared in the footnote in Ruysschaert (1959), and they provide the plausible hypothesis that it lists HM 1034, and this should be a typo for HM 1035 (27). However, it is certain that also HM 1034 was also part of the Collegium Romanum selection of manuscripts acquired by Voynich. This is because its bibliographical description has been preserved, and perfectly matches HM 1034. Its entry in APUG 3289 also closely matches this description.


I am grateful to Francesca Potenza for her kind and helpful support in this research.
The bibliogaphical note of the Aristotle manuscripts and the images of the Voynich MS were kindly made available by the Beinecke Rare Book and MS Library of Yale University, New Haven (CT). I am indebted to the University of Illinois, Urbana - Champaign, Rare book and MS library, and the Huntington Library, San Marino (CA), for providing illustrations of their Aristotle manuscripts. I am grateful to the Vatican Library / Bibliotheca Apostolica Vaticana for the digitisation of several of the manuscripts among Vat.Lat.11414-11709.


The account of Voynich's acquisition of manuscripts from the Society of Jeses has been updated significantly in the first half of 2023. For all details, see here.
For more details about the composition of this collection, see here.
See Potenza (2022). This information is also included here.
The photographic copy has shelf mark Arch.Bibl.109. It is described in some detail here.
Strictly speaking, the books were sold to Pope Pius X and donated by him to the Vatican library
This identification of Ruysschaert's handwriting is reported in Potenza (2022), and credited to Paolo Vian of the Vatican library.
Ruysschaert (1959)
This may be compared with comments related to another manuscript from the same collection, see here.
She was Voynich's secretary from 1915 until his death, and later Kraus' secretary. These annotations must have been made sometime after 1937, when these bibliopgraphical slips were found by Herbert Garland in Voynich's London shop, and sent by him to Anne Nill in the US, see here.
De Ricci (1937)
In Ruysschaert (1959) on page vii, in footnote 3, transcribed here.
He lists Huntington manuscripts HM 65 on p.47 of De Ricci (which is a copy of Ptolemy's Almagest) and HM 1034 on p.82 (Isidore's Origenes), but not HM 1035.
See Dutschke (1989). See online: >>HM 65, >>HM 1034, >>HM 1035
Dorez (1897)
Ruysschaert (1960)
As stated in the description of HM 65. A digital image of the binding of HM 65 is >>visible online.
See for example a >>digital scan of the dorso of another Leoni manuscript.
The bibliographical slips are dated to the 18th or 19th century by Ruysschaert (1959), or even more specifically after 1849 by Pócs (2017).
It is perhaps ironic, that I was able to find these manuscripts using the index in De Ricci (1937), which was composed by the same Anne Nill who put the question mark on the paper slip shown above.
From information collected by Rich SantaColoma in the Grolier Club Library in New York. Voynich evidently used several labels for his manuscripts. The older H- and J-series, were renumbered into an A-series during his move to America. This is further confirmed in Wikins (1927) p.79, transcribed here. It still requires further analysis.
This scan is publicly available >>here.
I am grateful to the University of Illinois for a digital scan of this page of the MS.
This could be compared to a similar entry on MS Vat.Lat.11418 fol.1, which is from the hand of Coluccio Salutati (cf. Ruysschaert, 1959). If it is confirmed to be the same hand, the history of this MS is further complicated.
These are the Didymus MS now in the Morgan Library and the Marcanova MS now in Princeton. For all details related to this analysis, see this page.
For more details, see here.
I am grateful to Francesca Potenza who inpected the MS for this purpose.
This is mentioned in the Huntington guide, as part of the descriptions of both HM 1034 and HM 1035.


Contents Home Map
Copyright René Zandbergen, 2023
Comments, questions, suggestions? Your feedback is welcome.
Latest update: 15/09/2023