In this way the pressures of the multitude and diversity of authorita-tive opinion, already articulated in the previous century by Peter Abelard (1079–1142), were heightened by the development of reference books, from indexes and concordances that made originalia searchable and to the large compilations that excerpted and summarized from diverse sources.

Even if the Speculum was copied only in parts, Vincent of Beauvais exposed the reader to multiple opinions on any topic he discussed. Neither the concordance nor the encyclo-pedic compendium resolved the textual difficulties or contradictions that they helped bring to light. Vincent explicitly left to the reader the task of reaching a final conclusion amid the diversity of authoritative opinions that might exist on a question: “I am not unaware of the fact that philosophers have said many contradictory things, especially about the nature of things. . . . I warn the reader, lest he perhaps be horrified, if he finds some contradictions of this kind among the names of diverse authors in many places of this work, especially since I have acted in this work not as an author, but as an excerptor, that I did not try to reduce the sayings of the philosophers to agreement but report what each said or wrote on each thing; leaving to the judgment of the reader to decide which opinion to prefer.”161

Weighing in at some 4.5 million words in four parts (the last of which was composed and added after Vincent’s death) and divided into a total of eighty books and 9,885 chapters, it is likely the largest reference work in the West before 1600.