It seems that this general discussion is taking place over three current threads on the General Poly Discussion forum - and has generated some really interesting discussion with excellent points being made by a number of different individuals.
Some general takeaways that resonated with me along the way -
Relationship styles that we might currently describe as poly (multiple loving relationships with the knowledge and consent of all involved) have been happening since the dawn of the human race, even if not generally prevalent.
There was a significant amount of "poly type" relationship experimentation during the hippy culture of the sixties. From that general culture, Morning Glory Zell coined the term "polyamorous" and then defined it as
the practice, state or ability of having more than one sexual loving relationship at the same time, with the full knowledge and consent of all partners involved.
And really - or so it seems to me - she did a really nice job of summing up this certain type of relationship style that had been around for a very long time (but which had received increased attention in the sixties).
And although she wrote about how she practiced polamory, that obviously does not mean that everyone would have to practice poly in the exact same way to be called polyamory by her definition - because that is NOT what her definition says.
And while the Zells should be credited with offering a specific term to describe this relationship structure and then defining it, we must remember that they did not invent it - they just did a nice job of presenting the key characteristics - multiple, loving, knowledge, consent. The term "polyamory' is probably as good as any (despite its mix of Greek and Latin roots) - although I personally don't think it rolls off the tongue very easily.
I suspect that the problems surrounding the defining of polyamory arise from those who to want to add more requirements to what "true poly" should be, above and beyond "multiple, loving, knowledge, and consent". (such as heirarchical poly is not true poly, V's are not true poly, parallel poly is not true poly, etc).
Obviously, however, one should not call "cheating/adultery" polyamory - there is, after all, a definition that is generally accepted throughout the poly community and utilized by the most well known authors. But while it is obvious that adultery is not poly, perhaps we should not be so quick to judge those who have relationships that we might personally find to be less than ideal examples of polyamory. It is a credit to the quality of the Zell's definition that it - along with very close variations - continues to be the most widespread definition among poly authors and the poly community in general to this day.
(Kevin wrote)
there is nothing unethical about the way poly is generally defined
And further -
that general definition defines the ethics of polyamory -
knowledge and consent (one does not have to go any further). For a relationship to be poly (by definition), there must be knowledge and consent. Any other "ethical requirements" beyond that are superfluous and just a matter of personal preference.
(That said, I also have certain personal preferences and biases - but would not seek to impose them on others - other than pointing out the inherent issues in a polite, open discussion, such as recommending certain resources to the newbies who arrive in search of unicorns).
Just a few more cents worth,
Al