The right to keep and bear arms is a political right, but its rationale begins in the state of nature. In John Locke’s 2nd Treatise, he considers it almost self-evident that “I should have a right to destroy that which threatens me with destruction,” and he calls the precept a “fundamental law of nature.” In the state of nature, this right may take the form of wielding a rock or a stick against a single adversary, but in civil society the right of self-defense takes different forms. The primary change that takes place in civil society is that, under most circumstances, the right to punish an aggressor is taken out of the hands of the individual and reserved to the state. Only when a person is in immediate danger, and has no opportunity to seek protection from a magistrate, does he reclaim what Locke describes as his original “liberty to kill the aggressor.” Locke’s 2nd Treatise, however, does not extrapolate from this natural right of self-defense to any political teaching on the arms that a citizen may or may not keep for this purpose.
Still, these arguments from Locke could be interpreted to justify the right to keep and bear arms—as a political extension of a people’s original right of self-defense—and many Americans did interpret that right in this way.