BOOK REVIEW: THRILLER : It’s Sort of Like ‘Mad Scientist Meets Jack the Ripper’ : MACHINE <i> by Rene Belletto</i> , <i> Translated from the French by Lanie Goodman</i> ; Grove Press, $21, 364 pages

Rene Belletto gives us fair warning. On Page 5 of this thriller about a French psychologist who invents a machine that allows him to literally get inside a patient’s head, the hero’s wife, Marie Lacroix, is described as having a body “just as perfect, just as firm and supple, at 35 as it had been at 25.”

Well, well, we think. Perfect bodies abound on the pages of Playboy, but not in serious literature.

Then, on Page 10, the hero, Dr. Marc Lacroix, is described as having “slender, delicate hands and a handsome, angular face that bore a striking resemblance to certain El Greco paintings of Christ.”

Oh my, we think. There has to be a crucifixion coming, and nothing subtle about it, either.

Sure enough. The land of Proust and Gide, Voltaire and Sartre can, it seems, produce novels just as swift and slick and shallow as anything an American with both eyes on a movie deal can concoct, right down to the jump cuts and the one-sentence paragraphs.

Lacroix develops his machine out of scientific hubris, of course, but his ostensible motive is benign enough: a therapist’s desire to know what it’s like to walk a mile in somebody else’s frontal lobes. His first subject (after a test run with a couple of dogs) is Michel Zyto, a psychopathic slasher who may or may not have intended to kill one of his victims.

But, as tends to happen in thrillers, the experiment goes wrong. The machine doesn’t just give Lacroix a brief sampling of Zyto’s mental processes, as intended: It effects a total and permanent swap, putting Lacroix’s mind into Zyto’s body and vice versa.

Somewhere in here, despite Belletto’s straight-faced pseudo-description of the workings of the machine--the Umay 12 and Cray 6 computers, the electric shock that has “depolarized the neurons . . .and permeated the membranes, thus permitting better . . . assimilation of nerve impulses”--we realize with a smile that we’ve seen this gizmo before.

In the Saturday morning cartoons of our childhood, the mad scientist would fasten electrodes to the heads of two captives, chortling: “Now, I will put the cat’s brain into the canary’s head and the bird brain into the cat. If this experiment works, I will RULE THE WORLD!” He would pull the switch; Tweety would meow and Sylvester chirp.

Actually, the cartoons often spun this fantasy more interestingly than Belletto does. Here he has a chance to rework themes of double identity and flawed creation explored by Mary Shelley, Stevenson, Dostoevsky and Conrad, among others, but he hardly makes the effort; bent on manipulating us with fear and suspense, he turns the novel into what its title suggests--a mechanism designed simply to ensure that its pages get turned.

Zyto, in Lacroix’s body, has to worm his way into the doctor’s cozy professional and family (and even extramarital) life without arousing suspicion. Eventually, he figures out that he can use the machine to enter younger people’s bodies and become, effectively, immortal.

Lacroix, inhabiting Zyto’s body and therefore a fugitive, has to penetrate the slasher’s underworld haunts to get the weapons needed to counter him.

The point of all this isn’t any new insight into human nature, but rather a gratuitously ugly climax.

The thriller, after all (except in very expert hands, such as John Le Carre’s), is a reactionary form. The attitude underlying Cold War thrillers was that ordinary people could live in an illusion of democracy and humane values only because covert operatives, fiction’s Bill Caseys and Ollie Norths, were doing the dirty work needed to protect them--and thus, in a sense, were their moral superiors.

Novels like “Machine” play on our fear of crime and our itch for extralegal revenge by creating villains whose evil is total and irremediable. Lacroix’s desire to help Zyto is exactly what gets him into trouble. No amount of therapy can cancel out the menace that the psychopath represents. Only a bullet in the head will do.