The Libellus de Diversis Ordinibus was written in the 1130s or 1140s, probably in the diocese of Liège, a recognized centre of religious and intellectual activity at the time. It is a description of the similarities and differences among the various orders of monks, canons, and hermits, and, though clearly a contribution to a contemporary debate, is more analytical than polemical. Its unknown author, 'R', perhaps a regular canon, builds his case by
demonstrating how each order and profession corresponds to a group mentioned in the Old Testament: thus prefigured and performing their proper functions they all fill a legitimate place within the unity of the Church.
It is an invaluable source for religious life in the twelfth century, offering detailed insights into contemporary assumptions and practice.
Libellus de Diversis Ordinibus et Professionibus qui Sunt in Aecclesia