Hellbent and Homeward Bound : THE FOOL’S PROGRESS <i> by Edward Abbey (Henry Holt: $19.95; 485 pp.; 0-80500921:3) </i>

One fine Arizona day, Henry Lightcap’s third wife storms out the door for good. Her parting words consist of a message of magnetic letters arranged on the refrigerator door: “Go To Hell Henry.” After Henry eyes the muzzle of his .357 Magnum and weighs her advice, he decides instead to return to his roots in Stump Creek, W. Va.

Thus begins The Fool’s Journey. Henry’s decision has therapeutic motives, but before the journey can heal his fresh wounds, it must reopen old ones, and Abbey’s sharp, surgical prose does this through memories and flashbacks. Soon we realize that like the road that his wife suggested, Henry’s journey is also paved with good intentions. The two may even lead to the same place.

Abbey relates an account that is heartfelt without sounding sentimental. Henry’s companion, a dog with lung fungus breathing its last days on Earth, could have become an easy source of emotional manipulation. Instead, its acceptance of its fate on this death trip helps Henry’s own will to live.

Henry tries to relieve his friend’s pain with medication, and he prescribes the same for himself. It’s as though Kerouac was on the road again, retracing his steps with the added burden of years of disillusionment. But this time, instead of an adrenaline-induced narrative, our hero is on a diet of Demerol and Dilaudid. Not that the prose drags in the indifference of a drugged stupor: Henry turns potential self-pity into sympathetic insight, and his altered states are meant to dilute an already acute state of awareness.

His path is peopled by Rednecks, Ethnics, Feminists and other assorted characters from central casting. While their immediate recognizability makes them seem cut straight from the cloth of life--we have all encountered them, certainly--they remain two-dimensional patterns. Perhaps Henry’s own extraordinary pain isolates him from the everyday misery of others, yet one expects a greater empathy from a man equally at home with the Texas Troubadours as Gregorian chants.

At other times his minor characters are portrayed with a finesse that goes beyond the broad stroke. After giving the once-over to “an Asiatic type who looks like the latest refugee from Ho Chi Minh City,” he pauses to consider “the images of fire and torture and loss . . . that . . . torment his sleepless nights. Hunan, the poor devil, like the rest of us, too human for his own good.”

A similar problem exists with the friends he revisits along the way. Our first impression is that they seem more like caricatures than characters--the real estate shark, or the guru whose alleged holiness allows him to hover inches above the ground. Once Abbey gets past the self-imposed stereotypes, though, they come alive. To the extent that he seeks to expose those among us who traffic in greed and self-deception, his exaggerated characters may elicit smugness instead of an internal reflection.

Abbey is especially entertaining when he departs from the cynical sensibilities of his main character. On one occasion, a general passing out Purple Hearts during a publicity tour of a hospital takes a wrong turn into a gonorrhea ward. More intent on ceremony than chitchat, he’s all but oblivious to a hillbilly patient who recounts his dalliance with a country girl, then continues with his buddy’s saga: In the heat of passion and battle--several incoming rounds suddenly interrupt the soldier’s lovemaking--he ends up deflowering the girl’s pet pig. Forced to pay extra for the privilege, he must endure insult to injury when the witness suggests, “Homer should of done the right thing by that pig and married it.”

Henry Lightcap’s checkered resume includes graduate work in philosophy, and for him, philosophy offers more than an examination of life; it is life itself. He lives less in the world of ideas than of ideals, and living up to the most elementary ones pits him against those who merely give lip service to platitudes. His moral sense is too developed for a picaresque personality, yet down-to-earth enough to disqualify him as quixotic. Abbey creates a character equally at home on moral mountaintops as in banal valleys and caves. As a result, he is often at odds with himself--a sometimes-rogue who knows better.

The novel’s journey is interspersed with flashbacks that begin with Henry’s forefathers and continue through his past. While these chapters are admirable in their own right, the unfolding of the narrative suffers. For much of the way, we seem to travel down two distinct lanes rather than a two-way street where past and present meet. This becomes especially apparent when we compare the philosophical Henry with the younger one. Aside from a precocious Sartre or an occasional child prodigy, few children reveal their future mettle in a clearly discernible way. The child may be father to the man, but for the reader the proof of paternity rests more on the author’s word than on a personality resemblance.

Abbey is the author of a memorable novel, “Desert Solitaire,” about the development (i.e., destruction) of the Southwest, and “The Fool’s Progress” continues with this important theme. He understands, though, that ecological policies are personal as well as societal decisions, and that the roots of the ravaging go deep. In Henry’s case they go back farther than the remembered past, to the times when his white ancestors helped themselves to land from the other side of his heritage. Closer to home, he remarks after confronting some poachers who are also tearing the terrain with their vehicles that they are a “new breed. Not exactly men, not exactly women, but something they call ‘guys.’ ”

A blurb in the novel plants a coy disclaimer: “Eager literary types will probably compare the ‘Fool’s Progress’ to the late work of . . . Cervantes. . . . And they will be wrong.”

They are right: It is not, but neither does that detract from an eager recommendation.