DETECTIVE FICTION, like most other forms of genre literature, has recently submitted to the heavy-handed attentions of academic admirers. On the mean streets where Philip Marlowe pursued the shape-changing Velma and Sam Spade sent over Brigid O'Shaughnessy, young scholars now search for paradigms, structural patterns, or pyschoanalytic revelations. Happily, Robin Winks' Modus Operandi belongs to a different tradition --that of the literary-philosophical essay, a mixture of analysis, autobiography, and downright enthusiasm.

In his "excursion into detective fiction" Winks--professor of history at Yale and mysteries columnist for The New Republic--seeks to define and explain his fascination with writers as varied as Rosses Macdonald and Thomas, P.D. James, and William Haggard. Not unexpectedly, he uncovers numerous links between the researches of the historian and the investigations of the detective; but Winks' particular charm arises from the anecdotes--a childhood reading of "Richard Cory," a traumatic viewing of The Ox- Bow Incident--that reveal the growth of his fascination with incongruity, multiple viewpoints, and the hidden patterns of life.

Looking first at thrillers, Winks discovers movement and "that hint of being off balance" at their core. Thrillers teach that "no action should be without thought. . . . The professional doesn't point a gun unless he is prepared to use it, and he isn't prepared to use it unless the consequences are more desirable than other consequences are likely to be. Maturity means knowing there are options, having a sense of responsibility toward one's actions, thinking out the possible scenarios that might follow from opening this door, closing that one."

The mystery, however, "is primarily an investigation of character in relation to crime as society defines it." Winks downplays the puzzle aspect of detective fiction --he has no use for locked-room problems --and emphasizes the social dimension. The mystery illuminates a country, a society, a time, ultimately makes us rethink our values and examine our character, so that finally "detection becomes self-detection." Like an historian, the detective dispassionately tries to set the record straight; both accomplish this through an icicle-like detachment.

Besides these general reflections Winks enumerates the mystery's principal elements, provides stylistic analyses of Len Deighton and Adam Hall, and proffers capsule evaluations of favorite writers.

I have only two objections to this engaging essay. I suspect that Winks denigrates the locked-room puzzle because it transcends his social schema; Kingsley Amis seems more on the mark when he emphasizes that the impossible crime possesses a magical aura and a psychologically obsessive fascination, like certain rituals or recurring nightmares. More sadly, Winks also reveals a naive view of science fiction as space opera and technocratic mumbo- jumbo. In fact, both sf and the mystery attempt to clarify current social and political issues, detective fiction focusing principally on causes, science fiction on consequences.