Reprinted from "Gay Marriage: Why It Is Good for Gays, Good for Straights, and Good for America" by Jonathan Rauch, with permission from Times Books.

Try to imagine life without marriage. If today you are married, imagine that tomorrow, as though in a Kafka tale, you wake up to find that your marriage has never occurred. Moreover, your marriage cannot occur. There is no one for you to marry, or at least no way for you to marry the person you love. Your spouse may still be with you but now is not your spouse at all, but your "partner," or your girlfriend or boyfriend or companion or live-in lover or significant other or just, so to speak, your squeeze. You are not exactly sure how to introduce this person. You and your companion may think of yourselves as married, but your friends and family and coworkers may not see you and your partner (or is it companion? or lover? or friend?) as married, and certainly the government and the law do not.

Then again, perhaps you are single. Without the special bonds of marriage, and without the familial and social and legal support which marriage conveys, your relationship broke up during a bad patch a few years back. Now you are unattached, possibly looking for someone--someone whom you know you cannot marry. You are no longer a single person looking to marry or between marriages. You are between "relationships." That is not the same thing. Your future has changed, probably not for the better.

Now push your imagination a step further. Erase marriage not just from your present but from your past. Imagine looking back on a childhood and youth without the prospect of marriage. From the dawn of adolescence, when you first felt the beat of love in your breast, you have known that you would never marry anyone you felt passion for. Your first kiss was a kiss without hope of marriage. Your first date was a date without hope of marriage. When you discovered sex, it, too, was without hope of marriage. True love means, first and foremost, a love which ends in lasting marriage. For you, true love in that sense is not possible, and never has been possible, and you have grown up assuming it would never be possible. Your heart, now, is not the same heart. It has changed, and perhaps not for the better.

And now, if I may try your patience, push your imagination still further, to the outer limits of strangeness. Imagine not only yourself without marriage: imagine a whole community, a whole culture, without marriage. In your community, no one is married, no one has ever been married, no one ever will be married, and everyone has grown up from childhood taking the absence of marriage for granted. What is this community, your world, like? More unstable than the one you were accustomed to before your Kafkaesque metamorphosis, no doubt: probably less healthy, less happy; perhaps full of sex but not as full of love. It is a world of fragile families, a world marked by heightened fear of loneliness or abandonment in old age, a world in some respects not civilized, because marriage is the foundation of civilization.

Over time, many people in your marriageless world, possibly with you among them, succeed in forming and sustaining enduring attachments, and that success, against considerable odds, is a credit to human resilience. But, without society's help and encouragement, finding and forming lasting bonds has been hard. Even if, over time, most people in your marriageless world manage to pair off and act married, without marriage their relationships and their world are not the same. The law sees only individuals, never couples; the larger society is not sure what to make of these so-called partners. Their world remains incomplete, unfinished.

I think it is difficult, probably impossible, for most heterosexuals to imagine life without marriage. If, on the other hand, you are gay, you have not had to exercise your imagination much at all. For generations, homosexuals have come of age understanding that their love separated them from marriage instead of connecting them to it. They lived in a world turned upside down. As hard as it is now for heterosexuals to imagine life without marriage, that is how hard it was, until comparatively recently, for homosexuals to imagine life with marriage. If homosexuality has long seemed grotesque and threatening to heterosexuals, and if heterosexual convention has often seemed cruel and oppressive to homosexuals, the main reason is not the difference in sexual orientation as such but, rather, the marriage gap, which is really an imagination gap. Neither side could imagine the other's world. To be homosexual meant not to be married. To be married -- happily and honestly married -- meant not to be homosexual.

One of my childhood memories is of a day when, as I sat on the piano bench in the family room, it dawned on me that I would never be married. I have a distinct recollection of that moment. I did not discover or learn that I would never be married; I merely recognized that I knew it. That day was a long time, I think about fifteen years, before I understood I was homosexual. Throughout my childhood and youth, I had no notion of sexuality, but I did understand that marriage was not for me. Much later, after struggle and delay, I established caring relationships, but by that time I had grown up seeing life through the weird prism of marriagelessness. I assumed things would never change. I would never have two wings and fly, and I would never be married.