The New Critics regarded the language and poetic diction as most important, but the Chicago School considered such things merely the building material of poetry.
Crane said that “the only rational ground for adhering to one [form of criticism] rather than to any of the others is its superior capacity to give us the special kind of understanding and evaluation of literature we want to get, at least for the time being.” The question for the Chicago School (as it was for Aristotle) was always what the purpose of the theory of criticism was, what hypotheses were brought to bear by the theory about the nature of literature (for instance, whether it consisted of the words alone, or whether it was to be thought of as part of a larger context such as an era or an artist's life), and the definitions of words (such as the definition of tragedy or comedy).
Other key figures in the Chicago School were Norman Maclean, Elder Olson, William Rea Keast and Bernard Weinberg.
After this first generation, the most important critics to carry on the theory were Wayne C. Booth (who taught at the University of Chicago from 1947-1950 and again from 1962 until his death in 2005) and his contemporaries, Richard L. Levin, Sheldon Sacks, Robert Marsh, Arthur Heiserman, Ralph W. Rader, and Mortimer J. Adler.
Booth loosened the rigid categories of genre originally set forth by the Chicago School and moved the concentration away from poetry towards rhetoric.