By Kurt Vonnegut

Putnam. 302 pp. $21.95

WOODY ALLEN once observed that 80 percent of life is showing up. The other 20 percent -- the part that stands between me and stardom -- is making yourself likable, like George Burns, Jack Benny, Bill Cosby, or my pal (hah! don't I wish it!) Kurt Vonnegut. The amiable Vonnegut persona -- a wry man who is a tad curmudgeonly, but as moral as he can honestly be -- is, from book to book, Vonnegut's most substantial continuing creation. Many people may be just, or think they are, but it seems that few of us have doing justice as our aspiration -- and they may do more harm than good. But if, like Vonnegut's narrators, they're not self-righteous, but are by some miracle filled with good humor, I find such people more than likable. I want their friendship because I trust their judgements.

Vonnegut's novels are ways to spend some time with this unself-righteous yet just character, who in this book is called Eugene Debs Hartke. In his combination of decent aspiration and flaws Hartke is a depressed everyman -- if we still thought everyman was a decent guy. Hartke cares for his mad wife and grandmother, but he also likes to romance middle-aged women when they're emotionally vulnerable. And he repeatedly counts the cost of being a Vietnam vet, though he sounds to me more like a sad, wised-up WWII dogface than a Vietnam desperado: "If I were a fighter plane instead of a human being, there would be little pictures of people painted all over me." In Vietnam, Hartke was known as "the preacher," and he is a preacher still. For all he has done and all he has seen have made him despair. Vanity of vanities, saith the preacher, or as Hartke quotes a friend, human beings are "about 1,000 times dumber and meaner than they think they are."

The last U.S. soldier out of Vietnam, Hartke teaches at a college for the rich and learning-disabled in upstate New York, until he loses his post because a character who sounds veddy veddy much like William Buckley finds his despair un-American. He then crosses the lake to teach at a segregated prison. When all the convicts escape and kill the staff of the college, Hartke's blamed -- for black convicts must have had a white mastermind. Put in prison himself, he writes this book about being the last U.S. soldier in Vietnam, etc.

But the plot for me is just a clothesline on which Vonnegut can hang out some simple truths, tell some jokes, give quick-change renditions of lives that almost always come to pratfall endings, make up a few fables of our hopelessness, and becomingly model his despair. That, for example, the American rich "had managed to convert their wealth . . . into a form so liquid and abstract, . . . that there were few reminders . . . that they might be responsible for anyone outside their own circle of friends . . ." (226.)

Or that lobsters are boiled alive.

Along the way, as always, Vonnegut shapes some parables to embody his disappointment in humanity and to remind us of what sound and fury we create while signifying . . . well, you know. In this book, Hartke recounts a science fiction story in which Vonnegut's favorite aliens, the Tralfamadorians, are using the earth to breed hearty germs suitable for space travel, so they can cover the universe with life. The T'dorians made humanity mess up nature to impose trying circumstances on their germs, weeding out weak bacteria-astronauts. So that explains the stupidity of human history! (And, from the Vonnegut/Hartke's p.o.v. what an odd desire on Tralfamacore's part: "To me, wanting every habitable planet to be inhabited is like wanting everybody to have athlete's foot.") In previous novels, you may remember, history was explained as a shipwrecked Tralfamadorian's way of sending a message back to his home planet, a savage semaphore system, with exploding bombs as dots and dashes. Vonnegut's mood has not lightened.

But then, why should it?

Still, considering what a worthless lot we are, why does Hartke/Vonnegut care so much, grieve so repeatedly? As if life were a long education in the unchanging senselessness of life, and the only residue of our previous ignorance is the ineradicable feeling that it might have been different (kinder? gentler?) So why act decently? "It could be . . . somewhere in the back of my mind I believed that there might really be a big book in which all things were written, and that I wanted some impressive proof that I could be compassionate recorded there." Vonnegut's despair is the sign that he believes life should be transformed, even perhaps that it could be -- though it won't be, of course, except for the worse. His sadness is the negative proof of the existence of, well . . . what? God? Or a big book somewhere that God long ago abandoned?

Poor man, I hope his despair continues.

Jay Cantor, a MacArthur Prize Fellow, is the author most recently of "Krazy Kat: A Novel in Five Panels."