Machiavelli's The Prince

  I found it pleasantly surprising that Niccolo Machiavelli addressed the point of gun control, even though he published his book in the early 1500s. ;) The following passage (with a few of my own additions in brackets) is taken from Chapter XX:

  Now, no new prince [or other kind of ruler, such as a president] has ever at any time disarmed his subjects; rather, when he has found them unarmed he has always given them arms. This is because by arming your subjects you arm yourself; those who were suspect become loyal, and those who were loyal not only remain so but are changed from being merely your subjects to being your partisans [or supporters] ... But as soon as you disarm your subjects you start to offend them [if they have any intelligence whatsoever], showing whether through cowardice or suspicion that you mistrust them; and on either score hatred is aroused against you.
  Then, since you [the prince] cannot stay unarmed, you are forced to have recourse to mercenary troops... And even if these mercenaries were reliable, they could not be sufficiently so to protect you against powerful enemies and against subjects you distrust.
  ... So, all things considered... I censure anyone who, putting his trust in fortresses [or military], does not mind if he is hated by the people.

  In other words, any and all rulers and countries are more powerful and have longer terms of success, if they build trust with their subjects, and give them arms. If a country full of armed loyal subjects, is attacked, the subjects will defend it to the end. However, when a country is full of citizens who rely on the government to protect them and are helpless to defend themselves, they will do everything to protect and save themselves, including siding with the enemy.
  Psychology will agree that when someone is attacked, their body enters a state of "Fight or Flight". Those are the two main options, and if the government deprives the country (full of people) of their ability to defend themselves, then flight becomes the only option. And what enemy would turn down an opportunity to attack a kingdom full of peasants, whom he knows will do nothing but run if he invades?
  Thus, a ruler who disarms his subjects, or makes it unconstitutionally difficult to attain/use them, neither trusts his people, nor has the best in mind for the country. What kind of people would elect a man who they know would willingly disarm them? History is full of examples of people that once disarmed and placed under the "protection" of their government and its hired mercenaries failed. Machiavelli even names a number of these incidents. The founders of the US Constitution knew this. Any historian will also tell you that history repeats itself. Even if Machiavelli wasn't actually talking about gun-control, I see no difference in the rules. Anyone who attempts to disarm his own subjects does not have his country's best interests in mind, and is destined to be overcome by another enemy.