Modernism is a term used to designate the creative period between the Industrial Revolution and contemporary (read post-World War II) re-examinations of the relations between style and substance. It generally refers to a rejection of the "rules" of art before mid-19th century, and to the tools brought to art because of social and industrial changes. All of the arts experienced parallel re-examinations, restructuring the artistic experience, the patron base, the relation between commerce and art, and the place of art in Mankind's "progress." A thorough study by Irving Howe, "What is Modernism?", serves as the basis for all subsequent discussions.