If a brief phrase that is common is used as it occurs in a source, the words should be in quotation marks. The source of every quotation should be given in a footnote or in the prescribed manner. It is of course the prerogative of the instructor to prescribe that no secondary sources may be used for particular papers. A student who uses a secondary source must remember that the very act of looking up a book or an article should be considered as a pledge that the student will use the material according to the principles stated above. A primary source is a document or artifact written or created during the period you wish to study.
Secondary works are books or articles written after the fact.
Rousseau is well known for his sharp criticism of contemporary society and his vision of radical social change. His statements about women, however, usually reinforced the existing order. . . . Rousseau's conservatism about women may well have served to make his radical comments about men's behavior more palatable. Kerber questioned Rousseau's reputation as a social critic, noting that he always endorsed conventional views of women's roles. Rousseau was a prominent Enlightenment philosopher whose statements about women usually reinforced the existing order.