So I found this dictionary of poly terms on one of my poly blogs that I read, and I thought this entry was super-interesting:
Line Marriage n : a term from the works of Robert A. Heinlein, science fiction writer, meaning a marriage that from time to time adds younger members, eventually establishing an equilibrium population, spouses dying off at the same rate as new ones are added, this is a different form of familial immortality than the traditional one of successive generations of children
It's quite a radical concept of course, and probably not my cup of tea, but I wonder if for some people (maybe for all of us a little) is marriage a way for human beings to claim a small piece of immortality? With the traditional marriage, we pass on our genetic material to our offspring and they might be fruitful and multiply, and so a part of us in the complex DNA code lives on. My birth family, for example, can trace its ancestry back over 600 years, or something like that. Chinese tend to keep exceptional detailed records in that respect.
On the other hand, for people who don't want children, how can they achieve a piece of immortality? Of course if you're rich, you can build a college or a hospital, something that you will be remembered for. But for those of limited means, perhaps this is another way, to build a family that doesn't rely on having children, and yet can grow into something that outlives any individual member. A seed that, watered with lifetimes of love and commitment, becomes a tree that shelters many for a long, long time.
I'm not sure I really buy into this idea either though. My father once told me that personal happiness was about growing old with your family and generations of offspring around you when you die. Of course, in Asian culture that respects elders, family and longevity, this makes perfect sense. Time is also very important in this culture, evidenced by the fact the Chinese calendar predates the Roman calendar by many centuries, and the aforementioned emphasis on generational history.
I guess when it comes down to it, I'm not all that interested in immortality, at least in the material sense. I don't want monuments over my grave, or a big crowd of mourners at my funeral. I'm only interested in living in the here and now, and not for the future. And being Pagan, I don't believe it all ends at death anyway.