According to his treatise, librarians should possess extensive knowledge, be skilled in bibliography, exercise sound judgment in book acquisition and offer great customer service.
[1] He chose a clerical career, became an abbé and lived most of his life in Rouen, where he accepted membership in the local academy in 1764, and taught in the city's college from 1764 to 1774.
He promised to emulate the great librarians of the past, such as cardinals Angelo Maria Querini (1680-1755) and Domenico Silvio Passionei (1682–1761), who served as librarians of the Vatican, Gabriel Naudé, creator of the Mazarine library, Johann Michel Francke (1717–1775), who created the catalog of the magnificent library of Count Bünau, minister of the king of Saxony; and Ludovico Antonio Muratori (1672–1750), priest, historian, antiquarian and archivist and librarian of the Ducal Palace of Modena, one of the foremost scholars of his age.
[2] On December 23, 1780, Cotton des Houssayes presented a discourse in Latin to the assembled faculty, entitled Oratio habita in Comitiis Generalibus Societatis Sorbonicae.
The first English translation appeared in 1863; Dana and Kent included it as a classic in their collection of works on librarianship of the seventeenth and eighteenth centuries, published in 1906 by McClure in Chicago.
The librarian must have sound judgment in book acquisition and have the ability to create a comprehensive collection, but he must practice selection to achieve genuine merit for his library.
He spent many years working on a monumental unfinished bibliographic manuscript to be entitled Histoire Littéraire Universelle, ou Bibliothèque Raisonnée, also Traité des Universités de France and Mélanges Bibliographiques.