I hope you don't mind if I make some observations and suggestions about the form of communication you're using, since there appears to be a little bit of culture clash at work right now. (I acknowledge up-front that a discussion of form isn't a critique of content, and at any rate, I'm neither a practitioner nor an evangelist of polyamory myself.)
In a threaded conversation, brevity is the soul of communication: a few clearly stated points are much easier to reply to than a long essay. (Your first comment communicated much more clearly than the subsequent ones; it's no coincidence that it was upvoted.) I completely understand the desire to expand more and more on a point in order to be more persuasive and less misunderstood, but in this format it's usually much more effective to keep it short at first, then reply to specific questions and objections. (Here on the Internet, there's much more of a tendency for people to gloss over long sections of text. You can mitigate this to some extent by bolding or italicizing the key points; clicking the "Help" link below the comment box tells you how to do this here.)
Second, the repeated "What If" questions stand out from the usual form of discourse. There's a norm on Less Wrong (not universal, but common) of stating the actual reasons that cause you personally to hold a position, rather than tossing things out to see if anything sticks. (People do regularly play Devil's Advocate, but even in this case they're listing the reasons that would be most persuasive to them if not for their objections). I'd find it more helpful and interesting if you told us which of these considerations actually lead you to rule out polyamory as an option for you.
Again, this isn't an indictment of your reasoning, just a note on what differences in mode of expression might be making this discussion less effective than it could be. (Reciprocally, please tell us if any specific aspects of Less Wrong writing style strike you as unnecessarily smug, uncritical, etc; that sort of input is extremely helpful to a community like ours, and we need to listen to newer voices to hear it.)
I appreciate the feedback. Once I respond to people's objections, I'll be on my way.
Many of us are familiar with Donald Rumsfeld's famous (and surprisingly useful) taxonomy of knowledge:
But this taxonomy (as originally described) omits an important fourth category: unknown knowns, the things we don't know that we know. This category encompasses the knowledge of many of our own personal beliefs, what I call unquestioned defaults. For example, most modern Americans possess the unquestioned default belief that they have some moral responsibility for their own freely-chosen actions. In the twelfth century, most Europeans possessed the unquestioned default belief that the Christian god existed. And so on. These unknown knowns are largely the products of a particular culture; they require homogeneity of belief to remain unknown.
By definition, we are each completely ignorant of our own unknown knowns. So even when our culture gives us a fairly accurate map of the territory, we'll never notice the Mercator projection's effect. Unless it's pointed out to us or we find contradictory evidence, that is. A single observation can be all it takes, if you're paying attention and asking questions. The answers might not change your mind, but you'll still come out of the process with more knowledge than you went in with.
When I was eighteen I went on a date with a girl I'll call Emma, who conscientiously informed me that she already had two boyfriends: she was, she said, polyamorous. I had previously had some vague awareness that there had been a free love movement in the sixties that encouraged "alternative lifestyles", but that awareness was not a sufficient motivation for me to challenge my default belief that romantic relationships could only be conducted one at a time. Acknowledging default settings is not easy.
The chance to date a pretty girl, though, can be sufficient motivation for a great many things (as is also the case with pretty boys). It was certainly a good enough reason to ask myself, "Self, what's so great about this monogamy thing?"
I couldn't come up with any particularly compelling answers, so I called Emma up and we planned a second date.
Since that fateful day, I've been involved in both polyamorous and monogamous relationships, and I've become quite confident that I am happier, more fulfilled, and a better romantic partner when I am polyamorous. This holds even when I'm dating only one person; polyamorous relationships have a kind of freedom to them that is impossible to obtain any other way, as well as a set of similarly unique responsibilities.
In this discussion I am targeting monogamy because its discovery has had an effect on my life that is orders of magnitude greater than that of any other previously-unknown known. Others I've spoken with have had similar experiences. If you haven't had it before, you now have the same opportunity that I lucked into several years ago, if you choose to exploit it.
This, then, is your exercise: spend five minutes thinking about why your choice of monogamy is preferable to all of the other inhabitants of relationship-style-space, for you. Other options that have been explored and documented include:
These types of polyamory cover many of the available options, but there are others; some are as yet unknown. Some relationship styles are better than others, subject to your ethics, history, and personality. I suspect that monogamy is genuinely the best option for many people, perhaps even most. But it's impossible for you to know that until you know that you have a choice.
If you have a particularly compelling argument for or against a particular relationship style, please share it. But if romantic jealousy is your deciding factor in favor of monogamy, you may want to hold off on forming a belief that will be hard to change; my next post will be about techniques for managing and reducing romantic jealousy.