Priority in collection development at the Institute Library has always been given to editions of texts and archival materials and to catalogues of manuscripts held in libraries around the world. There is a special strength in medieval philosophy and theology; but the collection is also very strong in history, law, liturgy, and literature. The published opera omnia of every major medieval figure, as well as the great multi-volume collections on national and ecclesiastical history, are all available in the Institute Library. The inventory of the library stands in 2000 at 101,900 books, with another 20,000 printed and manuscript books in microform.

Special Collections
Several important special collections have been made available by gifts of books and funds:

• The J. Reginald O’Donnell Microfilm Collection contains over 10,000 reels of manuscripts from nearly 450 libraries.
• The Henry Carr Memorial Collection of microfilms and CD-ROMs of letters of the popes that are preserved in the Vatican Archives was initiated about twenty-five years ago by Father Leonard Boyle and Father Michael Sheehan.
• The Gilson Collection has gathered together the approximately 1,000 items of Etienne Gilson’s published work and a number of personal documents.
• Father Leonard Boyle, as Prefect of the Vatican Library, gave us the microfiches of the several thousand early printed books that constitute the Vatican’s Palatine Collection, as well as a number of facsimiles of precious Vatican manuscripts.
• The late Norah Michener, a graduate of the Institute, donated several hundred books by and about Jacques Maritain and his followers to form the Maritain Collection.
• The Stathas Collection is a special holding of Byzantine materials, supplementing the resources of the Greek Index Project, with its computerized information access system for the approximately 40,000 Greek manuscripts of authors and works prior to AD 1600.
• The Campbell Collection, acquired by the Institute through the initiative of the Centre for Medieval Studies of the University of Toronto, contains nearly 3,000 items, mainly Old-English but also Middle-English and Celtic materials.
• The Whitehill Collection comprises material on northern Spanish art, history, and liturgy in the Romanesque period.
• The Guest Collection, nearly 3000 books and pamphlets on the history and archaeology of English monasticism, is the gift of Dr Gerald Guest. Along with 12,000 colour slides amassed during his visits to almost a thousand monastic sites in England over a period of thirty years, they constitute an exceptional resource.
• Dr Guest’s slides complement the Library’s own Slide Collection, which includes more than 30,000 slides for the study of art and architecture, archaeology, palaeography, liturgy, and history.
• The John Hine Mundy Collection contains the academic papers of the late professor of history at Columbia University (16 meters). Professor Mundy was interested in the history of medieval Toulouse as well as the Albigensian/Cathar heresy of the period; in military history and the history of warfare; and in urban history and the history of town planning. Besides the paper material there is also a large selection of maps, slides, photographs, microfilms, and CD–ROMs. A detailed catalogue is available.
• The Pamphlet Collection now houses over 3700 offprints, lectures and pamphlets on topics related to the Middle Ages. Most of these items are not found in journals, Festschiften, or other volumes in the Institute collection.

Recent Acquisitions
The Library annually acquires a large numbers of books, periodicals, and microfilms (many of them in series on standing orders from publishers and vendors) throughout the year. A selection of materials acquired recently is provided below.

• La Bible de Saint Louis: a facsimile of the three–volume Toledo Cathedral chapter manuscript (Barcelona: Moleiro, 2000–01), made in Paris ca 1231, containing an abbreviated biblical text and a series of allegorical commentaries. It is particularly famous for its several thousand coloured roundel illustrations of biblical scenes. Acquired with the help of the Friends of the Library and the Walter Principe Book Fund.
• 66 early printed liturgical books, including missals, rituals, pontificals, and devotional works, from the collection of Dr Joseph Pope.
• over 200 microfilms containing a wide range of manuscripts, including a number devoted to Suetonius and to Terence, donated by John Grant, emeritus professor of Classics at the University of Toronto.
• new microfilm acquisitions that are the gift of Denise Bouthillier, Wallace K. Seaton, and Timothy D. Barnes, including 54 reels containing the extant manuscripts of Peter the Venerable's De miraculis.

Electronic Resources
The Institute Library has 8,500 uncatalogued books on microfiche, and nearly 800 CD-ROMs and DVDs, including the Papal Registers (from Innocent III [1198] to Pius II [1464] conserved in the Vatican Archives, the CETEDOC (Corpus Christianorum) database of Latin Christian Texts, Per Litteras Apostolicas, and the In principio database of Latin manuscript incipits.

For complete list of these and other electronic resources unique to PIMS, see the page devoted to local links in the Internexus section of this site. In addition, there are a large number of uncatalogued CD-ROMS at the Institute Library. Please refer any questions to the Library staff.

The specialized holdings of the Institute are richly complemented by the Robarts Research Library in the University of Toronto, the John M. Kelly Library at the University of St Michael’s College (which has extensive collections in medieval philosophy and theology), and by the several other libraries on the Toronto campus, in particular the Thomas Fisher Rare Book Library (strong in early printed books and also in manuscripts).

The Robarts Library also has a strong collection of networked resources: they include Brill's New Pauly, the Patrologia Latina: The Full Text Database; the Thesaurus Linguae Graecae; Early English Books Online (EEBO), which contains over 125,000 titles listed in Pollard & Redgrave’s Short-Title Catalogue (1475–1640), Wing’s Short-Title Catalogue (1641–1700), and the Thomason Tracts (1640–1661). All these resources are accessible from Institute offices and from the Library. Off-campus access to licensed resources is now available through a service known as my.access.

The University’s network provides a range of other electronic resources, including: (1) collections of texts (such as Bibliotheca Teubneriana Latina, The Book of the Duchess: A Hypertext Edition, and Le Corpus Montaigne; (2) catalogues of books and periodicals (such as Bibliographie Nationale Française, and Ulrich’s on Disc); and (3) reference works (such as The Routledge Encyclopedia of Philosophy and the Encyclopedia Judaica); as well as (4) indexes to scholarly writing (such as the International Medieval Bibliography). On-line journal databases available include JSTOR, Project Muse (hosted by Johns Hopkins University Press) and subscription journals from several academic presses, including Blackwell, Brill, de Gruyter, Cambridge, Chicago, Oxford, Springer, and the Taylor & Francis Group.

This site contains an extensive index to Web resources: a review of local resources is provided in Terra cognita; detailed lists of general internet resources can be found in The Engines of Electronic Enterprise .