I don't think this is a very good argument and I see it all the time.
Benjamin Franklin literally proved lighting was electricity, proved that electricity could be conducted, and invented the lighting rod. Do you not think he foresaw new developments, innovations, technologies, and applications that would come from that? Or do you think Franklin saw the lightning rod as the culmination of what was possible regarding electricity?
http://www.americaslibrary.gov/aa/franklinb/aa_franklinb_electric_1.html
Franklin also invented a stove that transferred more heat into the surrounding room using a new design in the siphon. So he literally took something that existed and made it better. But that's only stoves, right? He could have never foresaw anyone doing the same thing with regard to anything else.
https://en.m.wikipedia.org/wiki/Franklin_stove
George Washington, who is called the Father of our country, was the General that led the Continental Army. He had served for years in the British military and was the British officer that led the attack against the French that kicked off the French and Indian war.
http://www.history.com/this-day-in-...-washington-experiences-combat-for-first-time
Do you really not think that Washington had the ability to to look back in history and see that several hundred years prior to his military career, that European militaries were fighting each other hand to hand with swords, axes, and longbows? Do you not think Washington was well read on the topic of military history? Do you not think Washington understood that weapons evolved to become deadlier and more efficient? Do you think he thought the advancement of weapons systems would stop?
Did you know the Saxons get their name from the weapon they wielded, a long knife called the Seax?
Did you know the word Celtic is derived from the name of an ax, the Celt?
Did you know the descriptor German comes from a word for spear, the Ger, thus Germans are men who use the ger (spear) or Ger-man?
Think about the questions I've posed.
It's well known that military necessity drives technological advancement, even in Colonial times they knew that. Did you ever watch the old show on the history channel Tactical to Practical, or how about Man, Moment, Machine?
The reason we revere the Founding Fathers is because they had great foresight and they got a lot right.
I don't want to see innocent people murdered. The Vegas shooting is a national tragedy. My heart goes out to the victims and their families. But you don't punish law abiding citizens for the actions of evil people. If that were the case all an (aspiring) despotic government (or foreign infiltrators, or ideological subversives) would need to do is facilitate a mad man to commit a heinous crime and then have free reign to crack down on the people's natural liberties. The point of the American system is that the government doesn't have the right, privilege, or power to infringe our second amendment, our right to bear arms. We possess that because we were born, because we are alive, because our Creator has bequeathed this to us. Just like a tiger has claws, and a wolf has fangs, and a rattlesnake has venom, we too have our weapons of defense and attack. The crazies out there will go to any lengths to destroy, we must be prepared to go to any length to preserve and create.
^^^This is why God and the Founders have given us the means to our defense.