LUST IS THE metaphor for the human condition in Philip Roth's novel, The Professor of Desire. His story of a young man's effort to arrive at sexual and romantic happiness is funny, written with a pungent Rabelasian wit, but marked by an underlying not of wistfulness. He portrays a dissatisfation almost inherent in living, the incompatibility of passion and peace and the transcience of happiness.

David Kepesh, the hero of Roth's novel, is a scholar of literature and lust. "Studious by day, dissolute by night" is David's motto although his career as a sexual prodigy only begins after he has won a Fullbright to study in London. There he meets two Swedish girls; Elizabeth, loving and sweet, and Birgitta, daring and wildly lascivious. The choice is between the hearth or the furnace and, characteristically, David wants both. For a while Kepesh manages to have that but Elizabeth flees the menage a trois and David eventually breaks with Birgitta, recoiling from the destructiveness of desire for her.

At once a slave to Eros and a master of repression, Kepesh struggles between these two facets of his character. But this set pattern of restlessness, dissatisfaction and destruction continues through his other relationships. He marries Helen, a beautiful, adventurous, femme fatale and then proceeds to try to domesticate her. Their marriage dissolves over quarrels about burnt toast and lost letters. The wreckage of his marriage gives rise to a period of depression and unwilling chastity in David's life. A young teacher named Claire rescues him, and David feels he has found at last a sure and steady happiness. But while summering with Claire in a house in the country, David feels his passion waning and realizes that within a year he will lose his desire for Claire, his most precious possession.

In some respects, The Professor of Desire recalls Roth's earlier, most sensationalistic and best-known novel, Portnoy's Complaint. The plots of both books are quite similar-two bright, young Jewish men who have an overwhelming obsession with sex. The Professor of Desire, however, is much more sophisticated and accomplished. While David first appears in the book as a brash, precocious adolescent, he develops and matures throughout the course of the novel, whereas Portnoy's Complaint is the story of retarded adolescence. The explicitness and concern with sexual identity remain in The Professor of Desire but Roth is less intent on trying to shock the reader through blatant exhibitionism. In Portnoy's complaint, Portnoy was a rebel who shamelessly flouted the conventions and laws of his world. He was a heretic whereas David is a devotee who, in his own words, approaches sex as if it were "sacred ground." In fact, what Roth seems to do in The Professor of Desire is to construct a kind of summary of sexuality, in which he attempts to integrate sex with other aspects of human experience. Passion is the book's central doctrine. It is a source of both aspiration and destruction, the most fundamental ingredient for survival and, in the struggle between license and restraint, the means by which human beings exercise their freedom. David's comparison of Claire's natural goodness with his own tormented personality suggests a kind of Calvinist philosophy in which there are the elect, those visited by natural grace, and those outside the pale who are doomed to wander in the shadows, vainly seeking salvation in each new relationship.

Unlike Portnoy's Complaint, David's Jewishness is a minor motif. Although he treats David's childhood, growing up in his father's Jewish resort hotel, humorously, Roth is not interested in painting the expose of American Jewish life that he did in Portnoy's Complaint. Judaism is mainly a symbol. The Jew as an exile and survivor is used in conjunction with Roth's depiction of the ceaseless quest for love which, when found, fades only for the search to be renewed. As one of David's students writes in an essay: "The search for intimacy, not because it necessarily makes for happiness, but because it is necessary."

Not surprisingly, in a book where a writer is writing about a writer, The Professor of Desire is rife with literal allusions. David's preoccupation with romantic and sexual fulfillment is allencompassing, affecting even his career as a professor of literature.

He teaches a course on the great novels of erotic desire and he writes his thesis on romantic disillusionment. His special subject is Chekhov and his interpretation of Chekhov reveals Roth's own intent in this novel:

(To reveal) the humiliations and failures--worst of all, the destructive power--of those who seek a way out of the shell of restrictions and conventions, out of the pervasive boredom and the stifling despair, out of the painful marital situations and the endemic social falsity, into what they take to be a vibrant and desirable life.

When David despairingly realizes his love for Claire is already withering and that he is only a victim of his own faults, he curses himself. He tells himself he is not one of those sympathetic lost characters out of Chekhov but the insane amputee in a story by Gogol who places an ad for the return of his lost nose. What Roth succeeds in portraying, though, with all the delicacy and poignancy of the Russian dramatist, is that Kepesh is in fact a figure from a Chekhov novel. Not a warped, disfigured monster but a man whose constant pursuit of love reveals the tragic-comic dimensions of our own lives.