Well, your disagreement notwithstanding....
What I learned was that...it was a fundamental belief of the society that a person had a right to bear arms. It was a given, something that did not need further argument or debate.
I'm sure you are aware that when dealing with a fundamental social assumption, all other debates grow out of how that assumption affects a particular issue.
Think of any fundamental belief we now have today to find a parallel. I offer Women's rights as an example. Although it took a while for women to get parity with men in our society; now we don't argue about their ability to vote or have equal opportunities in education and employment, etc.. No, our arguments are about nuances, like you see happening in the Forum threads concerning women in Combat Arms.
That was the situation back when the issue of the Second Amendment and the debates about militia vs. standing army occurred. The foundational assumption was that all citizens already had the right to bear arms...
...there was no need for a standing army since the pool of armed citizens provided a viable, and less threatening, alternative through continued use of citizen militias. That's why the opening clause provides for a militia as an explanation for the limitation on the military power of the Federal government, while the second clause makes it clear the People have an inviolable right to keep and bear arms which shall not be infringed.
This was made clear in United States v. Cruikshank (1876):
"The right to bear arms is not granted by the Constitution; neither is it in any manner dependent upon that instrument for its existence."
