Jonathan Rauch, the vice president of the Independent Gay Forum, is a prolific writer on public policy issues. His new book is "Gay Marriage: Why It Is Good for Gays, Good for Straights, and Good for America." Beliefnet interviewed him recently about why he believes gay marriage will be a boon for everyone.

You point out that many people's thinking has been pretty sketchy on gay marriage. Why is that so?
Marriage is like water to a fish. People take it so completely for granted that they've forgotten what it's for. On my book tour, I expected to be selling gay marriage to straight people and marriage to gay people. What I'm doing is selling marriage to straight people. A lot of married people come away saying this has given them a new appreciation of what my marriage is all about.

What do people think it's about?
The two standard misconceptions are that marriage is a contract between two individuals and therefore, no one else's business, or that marriage is just a piece of government paper that hands you a bunch of benefits and puts a state seal of approval on a preexisting relationship.

Those are both very shallow views of marriage. It is a package of benefits, and it is a reciprocal arrangement, but beyond that it's a covenant between the couple and their community. Community is the silent partner in every marriage. That's why we have big weddings and wedding gifts and anniversary celebrations and rings on our fingers. It's why people ask us how our husbands and wives are every day. That makes marriage unlike any other relationship in its bonding power and in its social status.

Some say that gays have a special view of the culture and relationships that isn't compatible with traditional marriage.
There are lots of ways to be an outsider. Gay people will never be exactly like straight people. It will never be just like being left handed. But I do think that a lot of the problems and pathologies of gay life histories--what my adversaries call the "homosexual lifestyle"--are in fact the problems of the marriageless lifestyle.

What about those who say gay marriage will destroy the institution?
You hear four basic claims. The "everything goes" claim, that once you break one boundary, you break them all; the claim that gay marriage will further sever the link between marriage and children; the claim that people won't take marriage seriously and will inspire straight people to take marriage less seriously.

Let's start with polygamy.
Same-sex marriage in fact reaffirms that everyone should have the opportunity to marry somebody that they choose. That's the principle of monogamy. If you think the purpose of marriage is procreation, then you should be for polygamy because polygamy likes lots of babies. Ask any Saudi prince. But if you think marriage makes it possible for everybody to get married and have a family, gay marriage is of course completely consistent with that. It gives gay people the opportunity to marry without taking that opportunity away from straight people. Polygamy, on the other hand, is a zero sum game. For every winner there are at least several losers. It's a very dangerous, destabilizing situation. That's why you don't find polygamy in liberal, democratic societies. It is not consistent with equal pursuit of happiness. So gay marriage is the opposite of polygamy.

Some say the answer is to get government out of the marriage business altogether, or to get religion out of the marriage business and let the government handle it.
What those two ideas have in common is they're trying to detach social marriage from legal marriage. Legal marriage is the license and all the changes in legal status that go with it. Social marriage is all the expectations that go with marriage, of not letting down your in-laws, of living up to what friends and family and neighbors expect. Religious marriage is obviously part of social marriage because it's one of the most powerful ways a community gets behind marriage.

If you get government out of the marriage business, it's much harder for people to know who's undertaken this remarkable obligation. You'd have to talk to people, "So what's your status? What kind of contract do you have?" It's very important to have a very simple in-or-out so employers and everybody else knows how to treat you. The genius of marriage is that it doesn't tell you what you have to do to be married. It just tells you where the boundaries are-what the rules are for entering and what the rules are for leaving. And it hands you this big box of tools.

What kind of tools?
Tools for caring for someone. It's very hard to care for someone if you cannot get access to the hospital room. It's impossible to confide in someone if you fear they'll be subpoenaed to testify against you in court; marriage obviates that.

You can go on down the list of so-called "marriage benefits" and see that they're really marriage responsibilities. They are the tools you need to be responsible for another human being.