BOOK REVIEW : Over the Edge Into Madness--and Back : FORCE OF GRAVITY<i> by R. S. Jones</i> Viking $19.95, 268 pages

Emmet, maltreated in childhood under the intimate savageries of a privileged family, lives odd and alone in New York City and teeters in the shallows of madness.

In his 20s, Emmet wears layers of clothes in the summer. He eats only raw carrots, finding reassurance in his shrinking body. All things are dangerous; to be small and well-wrapped is a sort of protection.

He keeps a meticulous diary of every block he walks, every taxi he takes, every remark addressed to him. Sticking colored pins in a map, he charts all the crimes reported in the newspapers; he stores months of old papers in neat piles; he has the world safely stacked and under control.

He keeps a dog and talks to him about the day’s events; he buys a cat to keep the dog company when he goes out. He scrimps, but his relatives are well-to-do. They make him go to a psychiatrist, and each week, he painstakingly makes up lies to tell.

It is the reined-in madness you might notice in a city passer-by; oddly dressed, talking to himself, gesticulating. But Emmet keeps his torturing panic under bare control by means of his rituals and fetishes. Then one day, his apartment is burgled and stripped, and he breaks.

He has his mail forwarded to General Delivery in Casper, Wyo., and tells callers that he has been killed in a car crash. He suspects the cat of plotting against him and of corrupting the dog. Returning the cat to the animal shelter, he throws money at the attendant, tries to speak, but only succeeds in repeating: “Cat.” His brother gets him into a psychiatric hospital.

This is almost the halfway point in R. S. Jones’ novel, “Force of Gravity.” Finely written as it is, and despite the author’s close imagining of Emmet’s condition, with its jerky rhythms of connection and disconnection, and its sudden lucidities and sudden wanderings, we may be in some doubt about it.

A novel whose protagonist is mentally ill risks being a novel about mental illness. It tends to be about deformity instead of about a person who is deformed. As long as Emmet moves alone through his clouds, he doesn’t seem quite human; perhaps there is something in this of the Greeks’ insistence that a man alone is not human, in fact.

The legend about a boy who grows up with no human contact and who is suddenly brought into society (Francois Truffaut’s “The Wild Child” or Werner Herzog’s “Kaspar Hauser”) only begins when he is taken out of the forest or the cave.

Jones takes Emmet out, resplendently. In the mental hospital, the society of the injured, this character so artfully but statically configured in his illness, comes to life. We get an explanation of his condition. His mother had killed herself by jumping from a window in his hotel room; he had been so traumatized that instead of calling for help, he had gone back to sleep.

What we needed, though, was not explanation but exercise. Among the tormented residents of the hospital, Emmet finds, despite their deformities, a living humanity. And by having to deal with them, he discovers that illness only affects life; it does not replace it. He is mad but he is also alive. And, as he comes to sense and we come to see, his madness is far from hopeless.

Jones makes a vital community out of the hospital; he makes Emmet’s encounters, collisions and entanglements vivid and affecting. There is Emily, who helps initiate him into this new world; she is funny and tough, but as we come to see, some of the toughest and most apparently lucid are among the most vulnerable.

There is Winston, his huge, gay roommate, who tries to claim him and ends up stealing his money. There is the more profoundly threatening Bruce, fast-talking and popular, who is convinced that Emmet is really John Lennon and who demands that he reveal himself. Bruce’s badgering, comical at first, threatens to break Emmet down; in a reaction that partakes of both harshness and health, Emmet strikes back, and it is Bruce who breaks down.

Finally, there is Louisa, a suicidal college student. Witty, kind and clear-eyed, she becomes Emmet’s adviser and comforter. But when she persuades him to escape, the roles reverse.

After making their way to a small town chosen at random in northern New York State, she spins out of control and goes to pieces.

Emmet, on the other hand, discovering a new strength, becomes protector and nurturer. At the end--part of this strength is to measure his own weakness--he is preparing to take Louisa and himself back to the hospital. He hopes--and we feel it as a real hope--to be able, eventually, to leave properly.

“Force of Gravity,” which begins as an artful construct, ends as a work of art. The author has discovered the sinew, the passion, the intimacy and the individuality under the estranging clouds of mental illness.

Next: Elaine Kendall reviews “Same Bed, Different Dreams” by Hugh Gross (Midlist Press).