If Rabbi Adin Steinsaltz lived in the United States, he would likely be on the cover of Science or Time. His fiction might appear in The New Yorker, and op-ed pages of metropolitan dailies would invite his views on politics and society.

"He is a genius of the highest order," says Dan Segre, a professor of international relations at Israel's Haifa University. "Steinsaltz has the sort of mind that comes around only every couple of thousand years."

Steinsaltz, who lives in Jerusalem, just spent two months as a guest at Princeton's Institute for Advanced Studies. A book he researched there is on similarities between the thought structures of modern physics and traditional Judaism.

Steinsaltz is as easy to approach as a man on a park bench with a chess set but no one to play against. "I'll discuss anything you like," he says. "To me everything is Torah." (Interpreted narrowly, the Torah is the Bible's first five books; interpreted broadly, the Torah is the entirety of traditional Jewish learning.) He adds, with a boyish enthusiasm, "I am interested in everything."

He makes a face when asked to talk about books he has completed. That's behind him; he is no longer interested. He has written a book on locusts and another on biblical zoology. "The Thirteen Petalled Rose," published in English in 1980, is acclaimed as a classic of Jewish mysticism. He is working on a detective thriller that takes place in Jerusalem and on a historical novel set in the second century of the Common Era.

For all his other activities, Steinsaltz's life work is a new edition of the 36 volumes of the Talmud -- the proverbially complex code of Jewish life and law that reflects rulings and musings of hundreds of rabbis over more than a thousand years. The Talmud's range of topics is encyclopedic: from defining the conjugal duties of men in different occupations to determining punishments for every type of murder; from debating the reasons for the Romans' conquest of Jerusalem to interpreting dreams.

Steinsaltz apologizes for the unusual hour of the interview -- shortly after midnight. Night is his favorite time to write and talk -- a preference he shares with illustrious rabbis as well as oriental despots from time immemorial. But, he explains, his choice is pragmatic rather than traditional. He has two small children and finds it easier to work at night. He says he is grateful to visitors because his best thoughts come when challenged to a debate.

Steinsaltz is a frail 5-foot-6, with a scholar's stoop. When walking, his limbs have an adolescent clumsiness. He sits at the edge of a chair, with feet drawn under the chair, and speaks with his hands always in motion. When he smiles, his blue eyes twinkle and his face looks youthful; at other times, he seems an ageless rabbi with a scraggly red beard turning gray.

He wears the casual clothing of secular Israel: light-colored slacks, open- necked shirts and sandals. His clothes are rumpled and a size too large for him.

In a matter of minutes, he turns an interview with a stranger in a Princeton hotel lobby into a conversation between old friends. He listens to a question intently, then redefines it and applies his dialectics. Steinsaltz links worlds others see as opposites: religion and politics, mathematics and mysticism, rabbinic law and modern Western literature. He is admired by Israel's far right that calls for settling the West Bank as well as by the left that demands Peace Now. At his Jerusalem academy, he chairs a weekly seminar on Jewish mystical texts, attended by a select group of scientists, socialist politicians and Orthodox scholars.

"He has a gift of shedding light on imponderable problems," says Paul Berger, a senior partner with the Washington law firm Arnold and Porter, who recently spent a sabbatical year in Jerusalem taking a class taught by Steinsaltz. "I could sit with him for endless numbers of hours."

At 45, Steinsaltz is emerging as an Israeli blend of Teilhard de Chardin and Buckminster Fuller, with a pinch of Jean-Paul Sartre in the bargain.

"He is a down-to-earth visionary," says Rabbi Steve Shaw of New York's Radius Institute, a Jewish think tank that sponsored recent American lecture tours by Steinsaltz. "He sees connections no one else sees. But he has his feet firmly on the ground. Although I have known him for almost 20 years, he remains an enigma to me."

Steinsaltz has met with Palestinian intellectuals in semisecret sessions in France and Spain. According to Gen. Yehoshafat Harkabi, Israel's former chief of military intelligence and an Arabist, who took part in one of the encounters, "the person who most fascinated the Palestinians was Adin Steinsaltz."

Steinsaltz comes from a family of left-wing intellectuals with roots in Eastern Europe. He knew his Marx and Lenin before he knew Jewish religious thought, and he and his childhood friends used to beat up their Orthodox contemporaries in Jerusalem alleys. He turned Orthodox at age 14, much to the dismay of his antireligious parents.

Steinsaltz now thinks of Marxism as "a cheap imitation" of the Talmud's dialectic and "not at all" the prophetic guide to history it claims to be. "There are no prophets any more," he exclaims, his arms high in the air. "The age of prophets is over."

The Bible is divine revelation and national history, read aloud at synagogue services. The Talmud is a ceaseless debate, studied by Jews in small groups or individually. In "The Essential Talmud," published in Bantam paperback in 1977, Steinsaltz wrote: "The Talmud is perhaps the only sacred book in all of world culture that permits and even encourages the student to question it . . . . The student must participate intellectually and emotionally in the talmudic debate, himself becoming, to a certain degree, a creator."

Steinsaltz is working on a complete translation from the arcane Hebrew of the rabbis and the complex vernacular of Aramaic into modern Hebrew, accompanied by his own explanation of every passage. It is a task no one has undertaken in 900 years. The last complete commentary on the Talmud was by Rashi, the greatest Jewish scholar of all time, a vintner who lived in France at the time of William the Conqueror and whose explanations are models of lucidity.

Thus far Steinsaltz has published six volumes of his Talmud. He has been involved in the work for 20 years; completion might take him another 20.

"The scope of Steinsaltz's work can only be compared to Rashi's," says Michael Berenbaum, director of the Washington Jewish Community Council and professor of religion at George Washington University. "But Steinsaltz is not just playing the scholar's game. He helps people understand the Talmud; he has revolutionized the way the Talmud is studied. His commentaries will live for centuries."

In all his various endeavors, Steinsaltz is a talmudist -- a compulsive analyst, a framer of dilemmas, a gourmand of debate. He does not give straight, or simple, answers; he delights in complicating an issue or summing it up in a story.

To illustrate the dilemma of the Lebanon war, he uses a parable from his own life.

For many years he was ill with an enlarged spleen. Doctors in his native city of Jerusalem kept postponing surgery. They warned that risking an incision would be like playing Russian roulette. They did not want to be held responsible. One doctor got ill the day the surgery was to be performed; on another occasion, another doctor postponed the operation at the last minute because he thought that Steinsaltz's overall health was not strong enough.

The more doctors Steinsaltz consulted, the less clear his choices became. Even if we remove the growth, the problem would return, said doctors who didn't really want to get involved. The illness is inherited, they pointed out, one of those genetic deficiencies that plague the Jewish people.

Specialists in Washington went as far as suggesting that the problem would go away; time might just be the best cure.

But, it seemed to Steinsaltz, the one clear-headed assessment was from a doctor who insisted that as time went on and the spleen continued to grow, surgery would become more and more risky. And nothing would be as dangerous as an inflammation requiring surgery in a hurry.

So cut, the rabbi finally said, let's not waste another day.

The surgery took place three years ago, and the patient is now "in good health, thank God. Never felt better."

Steinsaltz sees a parallel between his enlarged spleen and Palestinian terrorism: The invasion of Lebanon was "inevitable" and "a necessity." Given the Palestinians' "arms, training and motivation," eventually they would have had to attack, and thus Israel had to go to war sooner or later, and sooner was better than later. "There was no possibility of a compromise," he says, echoing the government's hawkish analysis. "Sometimes you can bribe or threaten and get a better or a worse agreement. But this situation with the PLO had to explode."

On the other hand, he withholds judgment on whether the incursion into Lebanon is "a just war." He is waiting to see how effective the war will be in channeling Palestinian nationalism toward a peaceful denouement, which Steinsaltz defines in dovish terms: an evolution toward statehood, similar to the Jewish community's progress toward independence under the British Mandate.

To his way of thinking, a war is justified only if it "straightens out things and solves a problem and not when it satisfies an emotion, such as vengeance or anger." If a war doesn't solve a problem, he says, and his arms come down hard on the armrests of his chair, "it is never justified."

Asked if he is troubled by the civilian casualties in Lebanon, Steinsaltz questions the validity of distinguishing between civilian and military deaths and says he is equally troubled by both. "The question is how much of it is avoidable," he reframes the question. "If a person holds a gun -- is he a different human being?"

He tells a story of one of his best friends who was a peace activist after the 1967 war, working with Arabs and arguing with Jews. The friend was killed in the 1973 war after he was surrounded by Egyptians and refused to surrender. "He fought to his last bullet," Steinsaltz says. "He was conscientious to the nth degree, anxious for moral and religious reasons." To Steinsaltz, the story suggests the complexity of individual reactions to war and proves "soldiers killed are still people."

"Even a justified war is never a nice thing," he says, but, ideally, a war should be "fast, well done, clear, with little anger" and close to the event that provoked it. The Six-Day War of 1967 was such a war--"a clear case of self- defense"--as were the 1948 War of Independence and the 1973 Yom Kippur War.

Today, as in the Sinai campaign of 1956, the situation is more complex, "with no direct military threat" hanging over Israel, only a prolonged period of terrorist harassment. But today's war is "clearer" than the 1956 war, he adds, because in 1956 France and Britain also were involved, and Israel did not have the ability to resist American pressure.

He finds the American image of war is combat as "stylized" as the one between medieval knights, with everyone else being innocent bystanders. "But modern war is different, even if it is done by angels who kill only the right persons," Steinsaltz says. "The totality of war is a fact of life. That's part of the complexity of modern war. There are no civilians any more."

Steinsaltz has a high opinion of the effectiveness of violence to change history for the better. "A war is not something to be admired or loved," he says. "But it can change the direction of events. And once it happens I accept it as I accept the death of my dearest friends."

For a man of the spirit, Steinsaltz is fascinated with violence.

Turning the other cheek is not morally superior, he says. To the contrary, turning the other cheek is morally wrong. The main idea of justice is if an act is wrong, "it is wrong whether it is done to me or to others. We believe that it is wrong for me to hit someone else and it is wrong for him to hit me too. It is not morally superior to be forgiving and forgetting, and it's not even convenient," he giggles, enjoying his own phrase.

He criticizes both the peace movement and Gush Emunim -- a quasi-religious movement sworn to annex the West Bank of Jordan. He says peace activists "have no positive program"; the Gush Emunim is pursuing "an anachronistic Zionism" that belongs in the 1920s when pioneers were establishing kibbutzim (collective farms). The two movements have strength because in his heart each Israeli belongs to both, he says. Even if an Israeli fights one of the movements, he can't help being in secret sympathy with it, because "the two movements are external images of how people really feel."

Years ago he was quoted as ready to even return to the Arabs portions of Jerusalem in exchange for real peace. Leaders of the peace movement feel close to him and seek his advice. He says he tells them that "to make it big in Israel they have to transcend the definition of peace as a negative term of no-war." Unfortunately, he says, peace activists "have a problem of having an enormous hatred for everybody who is not as peace loving as they are."

Steinsaltz's smile is impish; his criticism is without anger.

He is also close personal friends with ultranationalist Geula Cohen, who denounced Prime Minister Menachem Begin, her mentor of many years, because of the peace treaty with Egypt.

He volunteers the information that he was wrong on Begin. He could not imagine that Begin would ever become prime minister because of one thing: "He is too much of a gentleman." By that Steinsaltz means that alone among Israel's politicians, Begin has Central European manners, complete with hand kissing (Steinsaltz rolls his eyes), that dark suit and tie (Steinsaltz's lips curl in contempt) and a self-imposed ideal of nobility (Steinsaltz's eyebrows make clear how bizarre it is to have such a Christian, made-in-Warsaw concept in today's Israel).

But Steinsaltz defends Begin: "He is a softhearted person. He has real horror of bloodshed." Reminded that no Begin speech is complete without a reference to blood, Steinsaltz replies that whenever Begin speaks of blood it is always Jewish blood, the blood of martyrs, never -- never -- the blood of the enemy that had been spilled or ought to be spilled. With Begin, blood is a matter of "sentimentality" and "rhetoric"; part of his skillful adaptation of mannerisms from the Bible and from Eastern Europe. "A bloodthirsty person would call for the enemy's blood," Steinsaltz closes his argument.

"Begin's biggest fault is that he has no vision," Steinsaltz says. "He and Sadat may be considered equally good politicians. But Sadat had a vision." By that Steinsaltz means Sadat knew what he wanted to accomplish in the long run whether or not he could reach that point.

Steinsaltz believes in angels. His most personal book, "The Thirteen Petalled Rose," draws distinctions between different orders of angels -- beings that "constitute a permanent contact between our world of action and the higher worlds." While man is full of contradictions and has the capacity to rise and to backslide, angels are "eternally the same."

In Jerusalem, Steinsaltz heads a talmudic academy. He writes articles for newspapers and appears on radio and TV panels discussing politics, morality, social issues, art -- anything. Once in awhile he writes a science-fiction story.

"I do all these things because I am basically lazy," he says, laughing, and apologizes for the time. It is 5 a.m. "I fool myself. I create an illusion that I don't work because I am always doing something else, not what I should be doing."