Shmuley Boteach, the Chabad-educated rabbi and controversial author of "Kosher Sex," talks just like he writes — fast and loud.

He speaks loudly about subjects that most people prefer discussing in quiet, hushed tones.

"When you masturbate in marriage, you release sexual steam without furthering a dependence on your wife," said Boteach, his booming articulation of the word "masturbate" bouncing off the walls of a coffee shop.

"A survey in England showed that men who masturbate argue more with their wives. If you want to make love to your wife, or feel you need sex, and get rid of that urge through masturbation, you don't have to say you're sorry after arguments."

Hello, Shmuley.

An American who now lives in England, Boteach will speak about his new book at 8 p.m. Thursday at the Marin Jewish Community Center.

And as Boteach speaks, paying absolutely no attention to who may overhear, or what they may think, so does he write.

"Couples should leave no stone unturned in their sexual repertoire, always renewing the spontaneity and freshness of their relationship," the self-proclaimed maverick writes in a section of "Kosher Sex" entitled "Spicy Sex."

"The rule of thumb is that anything that enhances the love, excitement and intimacy of a marriage, while not compromising its sanctity or modesty, is always a good thing. Seen from this perspective, the Kama Sutra — its explicit nature aside — can be a kosher book."

And therein lies the rub.

Orthodox rabbis, according to the conventional wisdom of the last 2,000 years, do not sex gurus make. Nor do they give their hechsher to the Kama Sutra, oral sex or sexual toys, all of which Boteach has drawn inside the kosher pale.

And the controversy is not quiet. The head of United Synagogue, the umbrella group for many Orthodox shuls in Britain, has been attacking Boteach nonstop.

"He said on the radio that a rabbi writing about sex is disgusting," Boteach acknowledged. "So I said, 'Where should young people learn about sex?' He said, 'They will learn about it.' I said 'Oh, from television? From Playboy magazine? From their friends' snide remarks and jokes? From dirty porn publications? But learn about it from Torah, God forbid.'"

Boteach argues forcefully that the Torah has much to say about sex and relationships, and not just that husband and wife need to be sexually apart for a certain number of days a month.

Kosher Sex is a '90s style self-help book that draws on Jewish sources to argue that passionate sex with one's spouse is not only permitted by Judaism, but even encouraged as a way to foster a strong, loving relationship.

In his day job, Boteach is director of the L'Chaim Society, a high-profile Jewish education organization in Oxford, Cambridge and London.

But at the tender age of 32, he has already penned some 10 books.

Boteach's presence is felt the minute he enters a room. He walks with confidence, talks with confidence. He is Dr. Ruth with a kippah, beard, tzitzit, wife, six kids and tons of testosterone.

"Being an ordained rabbi makes you an authority on Jewish law, but what makes you an authority on sex?" he is often asked.

"What makes me an expert is simply this," he said. "I understand what sex really is. I am not speaking about myself. Judaism has taught me what sex really is: our innermost desire to be close to another human being."

There is absolutely no contradiction about a rabbi giving out advice on sex and relationships, argues Boteach. He feels no discomfort being called the "sex rabbi," and finds that fielding questions about sex and relationships from Jews and non-Jews, straights and gays, can be even more fulfilling than answering the more traditional rabbinic questions, such as how exactly one prepares food on Shabbat.

Judaism, Boteach declares, is a comprehensive religion that does not separate the holy from the mundane.

Listen to Boteach talk, and — if you have had no exposure to the Talmud — you could walk away thinking that it is an early version of "The Joy of Sex."

"Look at the Talmud," he says, "it is replete with it, replete with sex. Replete. Everywhere. What about the book the Ramban [a 13th-century rabbi] wrote to his own son, as a wedding gift, the Iggeret Hakodesh, the Holy Letter. It is all about sex. I quote it at length in my book. It tells him how to bring his wife to orgasm: 'Make sure you don't rush things, make sure you seduce her with words.' Brilliant stuff.

"Why is that not in a self-help book — that'll turn on Jews a thousand times more than telling them we want to make sure they don't use ancient burial grounds for highways. I'm not denigrating that, God forbid, but you can't only have that part of the circle, and not the others."

Thanks to Boteach, hundreds of thousands, if not millions, of beer-swilling, eye-popping readers who have never heard of Nahmanides or the Iggeret Hakodesh may have come across the name in a recent edition of Playboy, which excerpted some 5,000 words from "Kosher Sex," including the passage from the Ramban.

Boteach's critics, of which there are many, say the Playboy excerpt embodies all that is wrong with his approach.

The focus, Boteach claims, should not be how he could agree to appear in Playboy, but how Playboy would agree to publish his conservative views on pornography.

"This represents the infiltration of religious ideas into pop culture," he says with passion. "The final infiltration where religion, Jewish ideas and values become so compelling that even those who represent its antithesis have to admit its viability."

Did he buy the issue?

"Actually," he says, launching into an answer that can only be described as Clintonesque, "that is an interesting question. My brother brought the magazine from Miami, and my wife took it. I said, 'Debbie, this is it!' and got all excited. I wanted to see it.

"She said, 'I'll read it first.' and gave it back to me a few minutes later, with about 70 pages torn out. I sort of have the magazine and the advertisements, but the meat of the magazine seems to be elsewhere. So, no, I never really saw it."

When "Kosher Sex" was published last year, it drew fire from the Orthodox community. The London Rabbinical Court and the United Synagogue's Council of Rabbis issued statements that criticized the book for trivializing and sensationalizing sex.

But Chief Rabbi of Britain Jonathan Sacks stood by him, issuing a statement that Boteach was "one of the more creative and imaginative talents in our community [who] has been prepared to take risks in order to communicate an authentic Jewish message to a new generation."

Nevertheless, because of the outcry over the book, Boteach resigned his post as part-time rabbi at a synagogue in north London.

Boteach, who considers himself a Chabad Chassid, was dispatched by Lubavitcher rebbe Menachem Mendel Schneerson to Oxford 11 years ago, when he was 22, to set up a student organization. He was ordained by Chabad after studying at a Chabad yeshiva in Los Angeles and for three years at the Torat Emet Yeshiva in Jerusalem. He grew up in Miami.

Boteach's official break with Chabad came not as a result of his writings about sex, but before. A few months after the rebbe's death in 1994, he invited Yitzhak Rabin to speak at a forum.

Though he has been accused repeatedly of self-promotion, he is also a huge promoter of his faith.

"Judaism," Boteach argues, "is the Buddhism of the future. It is what Buddhism was to the '60s and '70s — a religion no one knew anything about beforehand, but which for many became the source of their spirituality…

"The essence of the Jewish faith is not to go to heaven, but to create heaven on earth, to have both simultaneously, to drink and say l'chaim — but on Shabbat with family; to have great sex, but with the wife whom you love; to make tons of money, but to give a big part to charity; to want to be really famous, but famous for doing good things.

"We have reached a time when people want to be successful professionally, be recognized, but not sell their souls in the process. We have the most sensually and sexually indulgent generation of all time, who also read 100 self-help books per year. The orchestration of the two is amazing — the age of Judaism has arrived."