NATURAL SELECTION
by Frederick Barthelme
Viking; 212 pages; $18.95
Not yet 40, and Peter Wexler is a crank. It has something to do with his belief that everybody is a liar or, as he puts it, "smug and self-satisfied and just close enough to the facts to get by." When young Holden Caulfield complained about phonies, it had the force of discovery. Wexler's grownup bitching sounds more than a little gratuitous. Wife Lily breaks the news sweetly: "These aren't great complaints, you know. They're tired, and small, and self-serving, they're vague -- if I weren't wife-of-wives I'm not certain I'd be...