NONFICTION : THE SPY STORY by John G. Cawelti and Bruce A. Rosenberg (The University of Chicago: $22.50; 253 pp.).

In their study of the evolution of the espionage novel, John G. Cawelti, professor of English at the University of Kentucky, and Bruce A. Rosenberg, professor of American Civilization and English at Brown, spend most of their time focusing on the works of five authors. They tell us that John Buchan, in his “The Thirty-Nine Steps,” set the pattern for the modern heroic spy story, that Graham Greene and Eric Ambler turned the genre “from a story of adventure to one of treachery and betrayal,” that Ian Fleming shifted the emphasis back to Buchan and, finally, that John le Carre carried the Ambler-Greene themes to even more complex and disturbing psychological conclusions.

Neither these nor the majority of the authors’ other observations--i.e. that Buchan and Fleming practiced clubman jingoism--should come as news to any thriller fan. And the newcomer may be dismayed to find that Cawelti and Rosenberg mention many of the surprise twists and denouements of the major works in the field. It is odd that essayists, in their effort to provide insight into a literary genre devoted to “clandestiny” (their word), should be so cavalier with its most prized secrets.