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Frequently Asked Questions

What is the Theological Commons?

The Theological Commons is a digital library of over 150,000 resources on theology and religion. Developed in partnership with the Internet Archive, it contains books, journals, audio recordings, photographs, manuscripts, and other formats dating from 975 C.E. to the present.

Please see the Acknowledgments page for information on our partners and sponsors.


How do I submit feedback about the Theological Commons?

We welcome feedback from users, including general questions, data corrections, and suggestions for improvement. When contacting us, please provide the web address (URL) of the resource in question whenever applicable.

We also encourage users to nominate materials for inclusion in the Theological Commons, although the materials normally must be in the public domain and either held by Wright Library at Princeton Theological Seminary or already digitized by the Internet Archive.

The Item Details page for any individual item includes a Submit Feedback button. In addition, the footer at the bottom of every page includes a Contact Us link.


How do you select materials for inclusion in the Theological Commons?

Selection of materials for inclusion in the Theological Commons is guided by the Library’s Collection Development Policy. Additionally, due to legal restrictions on copyrighted works, the Theological Commons only includes materials that are in the public domain or for which special permission has been obtained from the copyright holder. Typically, items published in the United States before 1929 are unambiguously in the public domain, while those published outside the U.S. before 1899 are presumed to be in the public domain. Such items constitute the majority of content in the Theological Commons.


What should I do if I cannot find an item in the Theological Commons?

If you cannot find an item you are looking for, there may be several reasons for its absence. The item may be under copyright or it may fall outside the scope of the library’s Collection Development Policy. Digitization of materials held by Wright Library at Princeton Theological Seminary is ongoing, and some items eligible for inclusion have not been digitized yet. Contact us to nominate materials for inclusion.


What subjects are represented in the Theological Commons?

The Theological Commons draws broadly from the fields of religion and theological studies, along with relevant material from ancillary disciplines (see above for details).

Distribution of Subjects
Protestantism18,801 (11.9%)
Missions18,106 (11.5%)
History12,200 (7.7%)
Catholic Church8,552 (5.4%)
Theology7,818 (5.0%)
Church History7,695 (4.9%)
Practical Theology7,555 (4.8%)
Language and Literature6,806 (4.3%)
New Testament4,345 (2.8%)
Philosophy4,003 (2.5%)
Bible3,906 (2.5%)
Religion3,619 (2.3%)
Worship3,574 (2.3%)
Music3,508 (2.2%)
General Works3,051 (1.9%)
Old Testament3,004 (1.9%)
Ecclesiology2,528 (1.6%)
Education2,239 (1.4%)
Social Sciences2,000 (1.3%)
Preaching1,942 (1.2%)
Bibliography1,536 (1.0%)
Psychology1,398 (0.9%)
Judaism1,097 (0.7%)
Fine Arts1,041 (0.7%)
Ethics837 (0.5%)

What are “Topics” and how do they differ from “Subject”?

In the user interface of the Theological Commons, Subject indicates a general research area, such as “Church History” or “Theology.” These terms are based on the Library of Congress Classification system, a broad taxonomy of knowledge commonly used by academic libraries to organize the physical books on their shelves.

By contrast, Topics, although they range from broad to narrow, typically provide a much more precise indication of the content of a given book. These terms are taken from the Library of Congress Subject Headings (LCSH), a controlled list of descriptive terms used in bibliographic records in most U.S. library catalogs.

The Topics links found on the Item Details pages throughout the Theological Commons should be regarded as a tool for finding some, but not all, related materials, rather than an exhaustive or entirely uniform system of classification across all materials in the Theological Commons. Topics are normally indicated only when the Format is “Book,” since the bibliographic records for books typically contain LCSH terms, whereas the records for other formats such as archival materials or audio/video typically do not. In addition, the specific LCSH terms, while standardized, have been applied by individual librarians over time as they have processed books in their libraries’ collections.


What institutions have contributed content to the Theological Commons?

The Theological Commons includes digitized materials from Wright Library at Princeton Theological Seminary and from 167 other libraries and archives nationally and internationally.


What does the “Switch to low-bandwidth mode” button do?

After clicking the Switch to low-bandwidth mode button, the user interface of Theological Commons adjusts to minimize the use of images and JavaScript. Please note that JavaScript is still required for viewing digitized texts (books, periodicals, etc.) and images (photographs and postcards), and for playing audio/video recordings.


For some books, the “Search within this book” option and “Copy to Kindle” button are unavailable. Why?

The digital text file used to search each book, and to create its Kindle version, has been generated by an automated process (optical character recognition or OCR). The accuracy of each software-generated text file varies due to factors such as the physical condition, typeface, page layout, and language of the original book.

To ensure a good experience for the reader, we limit the availability of the digital text to books with an estimated error rate of less than 20%, and we make this estimate known in the interest of full disclosure. (Click the Copy to Kindle button, when available, to see that book’s estimated error rate.)


When I download a PDF file and copy it to my e-book reader, the e-book reader says the document cannot be displayed. Why?

E-book readers, such as Kindle (excluding Kindle Fire; see below) or Nook, are designed only to display digital text, not digital images of pages from the physical book. The PDF files available in the Theological Commons include the images of the original book. Some e-book readers cannot display such PDF files.

By contrast, devices such as iPad and Kindle Fire are full-fledged tablet computers, not strictly e-book readers, and therefore those devices can display the PDF files from the Theological Commons.