The United States Supreme Court's decision on Thursday to strike down a Texas ban on gay sex, ruling that the law was an unconstitutional violation of privacy, was necessary and correct. To be sure, I have devoted much of my career to upholding the institution of heterosexual marriage, and strengthening the religious commitment of American society. But I know that religion is sacred precisely because it involves freedom of choice. This is not Iran. We don't want a society where police can barge into a couple's bedroom to determine whether they're practicing sodomy or not and whisk them off to jail.

Senator Rick Santorum, a man I admire and respect, said in a recent interview with the Associated Press that if the justices overturned the Texas law, "then you have the right to bigamy, you have the right to polygamy, you have the right to incest, you have the right to adultery, you have the right to anything." The Senator is wrong. We don't prosecute people in America for adultery. No court would throw a man in jail for cheating on his wife, even if he deserved it. There has got to be a difference between moral and ethical sin and religious sin.

Homosexuality and sodomy are not ethical sins. No one is being hurt, no one is being cheated, nobody's rights are being infringed upon. Homosexuality is a religious sin, analogous to other Biblical prohibitions, like not eating the carcass of a dead animal, or not sleeping with a woman during her menstrual cycle. In many ways, adultery is even worse, because it does transgress ethics. It involves deception and lying. But we don't prosecute people for adultery.

I don't mean to minimize these prohibitions. I am an observant Jew who takes the Bible seriously. But a man who eats shellfish--which the Bible calls an abomination (Leviticus 11:12: "Whatsoever hath no fins nor scales in the waters, that shall be an abomination unto you") is not immoral so much as irreligious. Likewise, a man or a woman who works on the Sabbath is not unethical. They haven't stolen from anyone. But they have contravened a Biblical injunction.

Senator Santorum and Justice Scalia are simply wrong. Saying you won't throw homosexual men into jail for practicing gay sex is not condoning homosexuality, just as saying that we won't throw a cheating husband into the electric chair is not condoning adultery. We don't have Kalashnikov-armed mullahs beating our women for walking in the streets without having their breasts hidden. We believe in the power of G-d's laws to be argued rationally and logically and to win arguments in the marketplace of ideas, rather than blowing people away for being infidels.

What percentage of the American population is gay? Ten percent? What percentage of the population is divorced? At least 50 percent. In addition, we have a rampant culture of womanizing, where men are conditioned to use women and discard them. And yet, what are we religionists obsessed with? Homosexuality! Who made this a bugbear of conservatives and religionists like me? Why do we squander all our credibility on the gay issue?

Our approach should be simply this: we believe in heterosexual marriage. We believe a man and a woman have more to offer each other through a diverse and complimentary relationship than the homogeneity of a homosexual relationship.

Having said this, we understand there are many gay men and women who have no inclination whatsoever to members of the opposite sex. To them we say they should be in responsible and committed same-sex relationships, even though we cannot equate these relationships fully with heterosexual marriage.

Let's turn our attention to the real enemies of marriage: Men who impregnate women and abandon them. Men and women who cheat on their spouses. Men and women whose commitment to marriage is so tenuous that they are prepared to divorce without first seeking extensive counseling. And finally, the huge explosion in men and women who insist on a prenuptial agreement before marrying, promoting their money over their hearts.

As regards the states with sodomy laws outlawing anal sex even between husband and wife, I (the author of a book called "Kosher Sex") say: Stop being ridiculous. I'd rather a husband and wife experiment, including by having oral and anal sex and trying out every sexual position, than use pornography to get excited. I would rather a husband have anal sex with his wife than leave him to think about another woman while having missionary sex with her. It's better to condone all sexual positions than to have men going to a whorehouse to experiment with positions that are forbidden to them in marriage.

But I'm getting ahead of myself here. There is another question raised by the Supreme Court case decided today: whether the U.S. government, or any government, has the right to regulate people's private, intimate, sexual behavior. This question goes to the very heart of democracy. Are our private lives just that - private? Or do my actions in private have an impact on public morality?

First, the basics. We all recognize and accept many legitimate government encroachments upon our liberty. Few fair people would object to the police stopping a man or a woman from jumping from the Brooklyn Bridge. You may think your life is your own, but it's not. Likewise, every responsible citizen would expect the government to stop drug addicts from killing themselves. Sometimes, the government has to save you from yourself. Likewise, the police will legitimately stop you from taking out a chainsaw and mangling your arm.

The same is true when it comes to sex. No one seems to have a problem with bigamy or polygamy being against the law. Indeed, from a logical standpoint, the illegality of polygamy seems grossly unfair. If a man has a wife, and then takes a mistress, it is perfectly legal. He can have sex with her and use her for her body without any legal repercussions. But the moment he takes responsibility for her, contractualizes the relationship, and makes an honest woman out of her by marrying her, they throw him in prison.

Now, I'm not advocating polygamy, a degrading institution where a woman is not afforded the primacy and exclusivity that marriage is designed to offer. If, even after you marry, you have to compete for your husband's attentions, you may as well have stayed single.

But that's my opinion--why should it matter? On my daily radio show, I 've interviewed polygamous wives who speak of the joys of the sisterhood of polygamous marriage. They argue that polygamy adds a communal dimension that monogamous marriage sorely lacks. Why, for that matter, should a woman be prevented from taking more than one husband, especially given the incredibly poor sexual performance on the part of most American husbands?

The same applies to incest, a grave offense under American law. Why should the government decide if a brother and sister may have sex or marry? Hey, it's a free country. And if you tell me it's to prevent birth defects, I'll respond, "Haven't you heard of contraception?"

So, why doesn't America have the right to deprive gay men of sex in the privacy of their own home? Why can't the police interrogate Mr. and Mrs. Jones about what they're doing between the sheets?

I believe that a brief detour into the highly controversial issue of gay marriage is helpful. Canada has just passed legislation allowing gay marriage, and many within the United States are arguing that America should follow suit, and not all of them liberals. Andrew Sullivan, a former editor of The New Republic who is openly gay (and with whom I debated homosexual marriage in Oregon), argued recently in Time magazine that conservatives should likewise embrace gay marriage as a way of making the gay subculture more conservative.

Mr. Sullivan makes a good argument. The United States should be encouraging gay men and women to be in stable and committed relationships. We need not elevate these unions to the same level as heterosexual marriage because of the way this dilutes the simple definition of marriage. Gay men and women can be afforded many of the legal benefits of marriage without it being called marriage. I oppose gay marriage because it's public and legal and undermines the age-old institution of marriage.

But what two gay men do in the privacy of their bedroom is totally different. Unlike polygamy or incest, no rational person can argue that two men having gay sex is going to undermine the legal institution of marriage. Those that do are probably more interested in attacking gays than protecting marriage.