 It is a popular and important document for it expresses the philosophy of librarianship.Cotton des Houssayes deserves the admiration from any librarian for his efforts on behalf of the profession.Cotton des Houssayes suggests in "The Duties and Qualifications of a Librarian" that the librarian possess all secular and sacred learning; he must be a professional theologian, and have an array of knowledge of literature, of the arts and the sciences.