Adultery in the Natural Interest : NO MAN’S LAND <i> by Martin Walser; translated by Leila Vennewitz (Henry Holt: $17.95; 160 pp.) </i>

Wolf is a German nationalist, but forget all the abominable meanings the term has picked up over the last century.

Think of Goethe, Schiller, Beethoven, pastoral nostalgia, sausages, comfortable bad taste, amiable pedantry, the Rhine and the touch of comedy that beguiled Mark Twain. Think neither of the soldier, the brownshirt nor the four-Mercedes industrialist, but of the romantic who lay in a meadow and thought cloudy thoughts.

Martin Walser, who writes mordant parables with comic tenderness, brings us Wolf, a peaceable nationalist. He fights in his own impractical way against the division of the Germanies.

Wolf is a one-man unifier. Years ago, he effected a small linkage westward by crossing over from the East. It wasn’t because of politics, but because he had punched his piano teacher for making fun of his playing.

Ever since, he has conducted an eastward unification by spying for the German Democratic Republic. His wife and his mistress both hold “cosmic” clearances in a West German defense unit. The mistress supplies him with documents in exchange for love and money, though the money goes entirely to pay for her husband’s psychoanalysis.

We get hints of Wolf’s unusual reasoning as the book goes along. But “No Man’s Land,” one of Walser’s best, lets it develop very gradually out of the comical and oddly moving predicaments that he finds himself in. Only at the end, when he has turned himself in and is standing trial, does he put his thoughts together.

Both Germanies “wanted to outdo the other in rejection,” he muses. “Each had developed hostility towards the other as the most vital ingredient of its self-awareness. And this was what Wolf wanted to remedy in a precarious field--that of armaments.” His remedy lies in “sabotaging the strength of each separateness.”

The paradox, of course, is that in order to conduct unification in this manner, your life becomes ludicrously divided. Wolf, of whom we become very fond, is a one-man schism.

We first see him hurrying home to give Dorle, his wife, a gold and turquoise necklace for her birthday. He has spent a month looking for just the right one. He loves Dorle dearly, despite his affair with Sylvia. Here, as elsewhere, he splits himself in his pursuit of one Germany.

They are having her boss, Meissner, over for dinner. First, though, Wolf has to tune his radio for instructions. The only message that night from his Soviet-East German handlers is warm birthday wishes for Dorle.

The dinner itself (see excerpt) is withering social comedy. Wolf and Dorle--she knows about his spying and about Sylvia, and it makes her sad--are two innocents. Meissner, a high defense official, is the new vulgarian of a nation whose soul is out of order because of its division.

The belief that Germany’s split has deprived her of her soul is a familiar one among post-war writers, notably, the late Heinrich Boll. But Walser’s handling of the message is uniquely alluring and suggestive. His symbols are musical in their flow. One of the best, in fact, refers to the piano.

Trying not to draw attention to himself, Wolf, the former virtuoso, still plays, but using only one hand at a time. He has become extraordinarily adept, but the result, as with Germany itself, is not music.

A mathematician neighbor is puzzled by this one-handed playing; he sets to work on a mathematical model. Toward the end, he is able to inform Wolf that a man who plays the piano with one hand--assuming he has two--has to be a spy.

When Wolf is with Sylvia he draws away from her volubility and whole-hearted ardor. “He wishes there were sunglasses for the ears,” Walser writes.

Afterward, Wolf realizes his feelings for Sylvia are real, that he betrays these feelings by his reticence, and that by having such feelings he profoundly betrays Dorle, his real love.

“He wishes he could have feelings he could approve of,” the author writes.

Wolf’s moral logjam begins to break up when he and Dorle go to the South of France to meet his Soviet and East German spy masters.

They are, in fact, no different than the West Germans he deplores. Above all, they are equally real. He decides to abandon spying and Sylvia, and turn himself in. During the trial that follows, he will give up his public reunifying and try for the personal kind--once he gets out of jail--with Dorle.

He has no great illusions about it. The necessary thing for his own sanity was to choose. How? “The country where one would rather face a court is the one to choose,” he reflects cautiously. But he adds: “Perhaps.”

The satire in “No Man’s Land” is deadly and exact. The comedy is quietly outlandish. But Walser is something more than a satirist.

I have mentioned his tenderness, and it is hard to describe. But it attaches us oddly to Wolf, to Dorle, to Sylvia and to the mathematician neighbor.

Wolf’s, and perhaps Walser’s, romanticism has the freshness of a clandestine activity. Wolf ponders the Rhine, as German romantics have always done. The gesture is contained, but not entirely deflected by his wry thought:

“It gave him a good feeling to see the Rhine churning along there so powerfully, as if it were being paid by the ton for the mass transportation of water.”

His trickle of pastoral longing is purified by the hard rocks it passes through. Wolf’s father was a concentration camp mate of the German Communist leader, Ernst Thaelmann. But it wasn’t politics that put him there. He drove the milk wagon that served the camp; he was caught in the humane act of smuggling out letters.

Wolf thinks of this at dinner with Meissner, his wife’s big-shot boss. He thinks of the poky Prussian villages his own family came from, with their comic rural accents and comic names. “He thinks of providing Meissner rustic detail from Ottstedt, Berlstedt, Ballstedt and Buttelstedt.”

The names are a clownish, nostalgic specific for a lost Germany; a rural Germany remote from history, but neighbor to its own soul.