AT THE BEGINNING of the 1970s, the two great thinkers of mystery fiction published their thoughts. Professor Jacques Barzun of Columbia University (with Professor Wendell Taylor of Princeton as co-author) brought out A Catalog of Crime. On the heels of this monumental study, British academician and crime writer Julian Symons published Mortal Consequences. In sum, Barzun argued that at its ideal best, detective fiction was not a novel, but a tale. That it should be aimed at the intellect, not at the emotions. That it should be a puzzle presented without the encumbrance of realism, social significance, probing of the soul, or of characters who were more than symbolic types. As might be imagined, Barzun did not approve of a lot of what he was seeing in 1970.

Symons, much happier with the deviations and mutations of the time, predicted that the future would see the intellectual tale wither "as more of the old masters and mistresses fade away" and its replacement by novels blending "psychology, clues, and social comment in the way that infuriates Barzun."

Thirteen years have passed, the future is here, and this winter's most recent offerings show that Symons was right. In fact, Symons' own entry is the only one in this group which comes near to satisfying Barzun's requirements. Now in his seventies, Symons is one of the masters who hasn't faded.

In A Criminal Comedy (Viking, $14.95) his 26th mystery, Symons gives us a puzzle which turns on a puzzle. The setting and characters are typical of the classic detective form -- with neither realism nor social commentary interfering with intellectual exercise. Puzzle one: Who is writing anonymous and apparently false letters alleging an adulterous relationship between Derek and Gerda? Puzzle two: Who kills two actors in this "criminal comedy" while they are visiting Venice?

It's all good fun and it's easy to see why the Mystery Writers of America declared Symons a Grand Master of the game. Sick at Heart

JONATHAN KELLERMAN, in Blood Test (Atheneum, $14.95), provides the best example among these books of what Symons foresaw, and of what I believe is becoming the central strength of the mystery form. The book combines complex characters, a plot involving accurate knowledge of a technical field, and a crime which is interesting in itself. The author is a clinical psychologist (six years as director of the Psychosocial Program at Children's Hospital of Los Angeles) and teaches pediatrics at the University of Southern California School of Medicine. He writes about sick children and sick minds from authority and experience.

Blood Test, his second crime novel -- the first was When the Bough Breaks -- takes us into the working world of a consulting psychologist with exactly Kellerman's specialty. The plot concerns the disappearance of a child who is dying of cancer, an odd set of parents, and an assortment of badly bent people.

The authenticity of its setting in the world of abnormal psychology is key to the success of Blood Test. But Kellerman is also unusually good at making his characters seem genuine humans and at telling a story of multiple murder which holds your attention. Gangsters

The Million Dollar Wound (St. Martin's, $16.95) is much like what television would call a "docudrama." It has the same appeals and, unfortunately, the same drawbacks. Max Allen Collins, the man responsible for the Dick Tracy comic strip since 1977, has welded a fictional Chicago private eye named Nate Heller onto the historical Chicago of 1942, when Frank Nitti was trying to maintain the control that the defunct Al Capone had held over the city, but without as much bad publicity. All historic fact. The plot turns on a struggle for control of the film industry through control of key unions. Also historic fact. Collins is dealing with a social phenomenon and an era with which he seems to be intimately familiar and he plays out a fast-moving story against a background of what actually happened. Thus the reader meets such historical personages as Barney Ross (boxer), Westbrook Pegler (gossip columnist), Robert Montgomery (actor), and Nitti (gangster) along with a cast of others, many of whom he suspects must be based on actual participants.

Collins has established himself as an authority on the Chicago underworld of this bloody and corrupt era with the previous novels, True Crime and True Detective, and I'll wager that gangster buffs will love his new entry in the historical fiction field (it comes complete with contemporary photographs). But if you aren't a gangster buff you find yourself wondering which of these politicians, cops and lawyers are fictional, and which of these incidents actually happened.

The historical approach, and the structure of the book, present a couple of other problems. Since it's told in the first person, working in all those famous folks makes the protagonist, inevitably, sound like a namedropper. Nobody likes namedroppers. And the narrative includes far, far too much flashing back to the battle of Guadalcanal, which was more important than whether the mobs will bring the movie industry to heel but didn't have much to do with Frank Nitti's Chicago or this plot. Legal Fictions

LIKE COLLINS, Stephen Greenleaf relies on both a private detective and nostalgia in Beyond Blame (Villard, $15.95). Like Kellerman, he adds a lot of interest to his effort by giving us what seems to be an inside look at an esoteric field -- in this case the business of insanity pleas.

The nostalgia is for the bygone days of Berkeley when it was the nerve center of the antiwar, anti-establishment protest movement. Greenleaf, who knew those days as a University of California law student, draws us into a plausible tale involving the savage murder of the do-gooder wife of a Berkeley attorney. The attorney specializes in saving killers on the grounds that their temporary insanity placed them "beyond blame" and the police suspect him of plotting to save himself with his own medicine.

Like Kellerman, Greenleaf obviously understands what he is writing about -- both the law and the community. However, although he handles the difficult business of dialogue with skill, and is also good at narrative action, he sometimes writes like a lawyer trying to write like a mystery writer. To cite a few unhappy examples of a tendency toward misfit metaphors, a suspect's house "loomed like a thunderhead in the gray flannel sky," a jury room is "tainted by the transparent husks of a thousand guilty verdicts" and a suspect's eyes are "frosted with the same miserable smear as the first time I'd seen him."

But the characters are real people with those real troubles to which our flesh is heir, the plot is clever, and not many readers are going to guess who's behind all this interesting evil.