MILAN KUNDERA SEEMS to have the best interests of his readers at heart. He begins The Unbearable Lightness of Being, his latest and rather ridiculous-sounding novel, with a direct statement of authorial concerns. This beginning, although a formidable piece of structural clumsiness, represents a kindly attempt to save the reader's time; while one does not get an explicit statement of Kundera's theme, one receives an engaging and straightforward account of what the author thinks. No grubbing about in the text for the Kundera reader.

At the start of the book, the narrator (apparently Kundera himself) addresses what he is pleased to call "lightness of being." Taking Nietzsche as his starting point, the narrator asserts that if all life is to be repeated infinitely, as Nietzsche claimed it would, life would have a demanding metaphysical heaviness. However, since life will never return (ignore what Freddy says), life is not heavy but light--comically and ironically weightless.

The consequences of lightness are several. Moral responsibility does not exist, for "how can we condemn something that is ephemeral, in transit?" History loses much of its reality. Talking of Robespierre, the narrator reveals that "the bloody years of the Revolution have turned into mere words, theories, and discussions, have become lighter than feathers, frightening no one." The present day is hardly more serious.

Kundera's novel is fortunately much better than this mouthy beginning promises. Kundera emerges as a personable, witty, and capably fluid narrator, whose story line is even and surprisingly thorough. It is puzzling, by the time one has finished the book, that a narrator as humane and accomplished as Kundera would have begun so blockily.

Kundera brings lightness of being to life by narrating, in classically simple form, the lives of two couples. Tomas is a top-notch Czech suregon; Tereza is his emotionally dependent mistress. Though Tomas loves Tereza more than any other woman, he makes love to as many women as possible; he is incapable of giving up his erotic friendships, though he is afraid of hurting Tereza. During the political unrest of 1968, Tomas and Tereza move to Switzerland; they are followed by Sabina, Tomas's next-best mistress. Some time later Tereza, deciding that she lacks the strength to live abroad, returns to Czechoslovakia, from which now there is no chance of returning. Tomas follows her back.

Tomas's life is undermined, meanwhile, by an article he wrote on Oedipus. Noting that Oedipus punished himself for a crime he did not commit, Tomas concludes that the political regime of his country, even if it did not intend to commit atrocities, should accept responsibility for what if has wound up doing. This article costs him his job as a surgeon; he descends to being a driver for a collective farm. By this time he is weak enough for Tereza's taste; she is happy with the final condition of her life with him.

The second couple consists of Sabina, who remains in Switzerland, and her intellectual lover Franz, Sabina, fond of infidelity, leaves Franz just as he leaves his wife for her. Franz, whose unfulfilled love for Sabina makes him more beautiful than before, attracts a student mistress whom he loves in Sabina's stead. He dies in Cambodia, on a trip for intellectuals who want to protest the treatment Cambodia has received. Confronted with muggers who demand his money, Franz chooses to fight them, remembering that Sabina admired his physical strength; he dies from the injuries they inflict. Franz is betrayed by his love and idealism; Tomas is overcome by Tereza's weakness.

EXPERIENCE IS A BURDEN because, seen from the lights of an unassuming intellect, it can be described and apprehended but not valued or shared; experience is light, even comic, but it no longer forms a bond between people. In narrating Tereza's life and in discussing the unsatisfactory nature of love, Kundera is at his very best; he brings the problem of lightness of being home in concrete and ironic terms.

Kundera lends his complete sympathy to Tereza, and his analysis of her condition prevents the reader from hating her weakness. Unity of sensibility is impossible for Tereza, for:

just make someone who has fallen in love listen to his stomach rumble, and the unity of body and soul, that lyrical illusion of the age of science, instantly fades away.

Tereza, very foolishly:

thought she saw her soul shining through the features of her face. She forgot the nose was merely the nozzle of a bone that took oxygen to the lungs, she saw it as the true expression of her nature.

Though she rejects "the joyful solidarity of the soulless," she has nowhere to turn, she is overwhelmed by the awful, non-personal intimacy of her aggressively vulgar mother Drawn to Tomas, she has become weak, for "True human goodness, in all its purity and freedom, can come to the fore only when its recipient has no power." If it is true that experience is light, it is also true that love, seen by the lights of the intellect, shrinks away to almost nothing to be certain that it is love she feels, Tereza can only love what is unable to control her.

It is in the condition of love, indeed, that the lightness of experience becomes most comic and most acute; Kundera's meditation on the problems of love are very fine. Sabina, looking at Franz's physically powerful frame, grows angry at Franz's refusal to use his strength outwardly in directing others' lives. He is too weak, she thinks, at the same time knowing that a strong man would be at least as offensive; she decides, in a terrible access of honesty, that it is love itself she cannot stomach. A more unsettling predicament is the failure even of dedicated lovers to achieve real intimacy. Tomas grows upset when a woman he made love to recalls an electric storm he cannot remember; though they were physically intimate, their experience was irreparably different. Even before Sabina jumped ship, Sabina and Franz were incapable of real contact. Kundera reports:

he listened eagerly to the story of her life and she was equally eager to hear the story of his, but although they had a clear understanding of the logical meaning of the words they exchanged, they failed to hear the semantic susurrus of the river flowing through them.