The Janus Intertextuality Search Engine

Link to Janus

NB: Since August 2013 the entire edited text of the Manipulus florum has been available for searching with Janus.

The Janus search engine, which was launched on this website in November 2008, was created and has been maintained by Andrew Kane, a doctoral student working under the supervision of Dr. Frank Tompa of the David R. Cheriton School of Computer Science at the University of Waterloo. The design of this search engine was inspired by the online anti-plagiarism service Unlike a typical search engine which only allows users to search for a few words or a phrase, Janus allows users to paste long passages or entire texts into the search field in order to generate an intertextuality report, similar to the "originality report" produced by Because the Manipulus florum was employed by late medieval and early modern authors as a resource for finding authoritative quotations that could be incorporated into their own compositions, this type of search engine is ideally suited for the use of scholars who want to determine whether, and to what extent, their author may have employed the Manipulus in this way. It should also expedite their own editorial work by quickly identifying some of the sources, whether they are cited as such or not, that are embedded in the text they are studying.

The search engine is named after the Roman god Janus, the two-faced deity of the threshold and gateway who looks forwards and backwards, because it can be used not only for determining how this florilegium may have been employed after it was completed by Thomas of Ireland in 1306, but also for identifying Thomas' intermediate sources written before 1306. In fact, the development of this search engine involved the use of about 50 quotations in the Manipulus that Thomas surely derived from the Moralium dogma philosophorum, an anonymous twelfth-century tract that was edited by J. Holmberg in 1929. Thanks to the efforts of Angus Graham, who transcribed Holmberg's edition and provided it on the Internet, it was not difficult to determine that Thomas employed the Moralium as an intermediate source that he mined (with varying degrees of accuracy) for classical quotations that are imbedded in it. Graham's transcription of the Moralium thus served as an invaluable tool that was used for testing the prototype of Janus and refining the software program in arriving at the current version of the search engine.