Copyright © 1994 Constitution Society. Permission is granted to copy with attribution for noncommercial purposes.
There is considerable confusion about the legal theory underlying the "right to keep and bear arms". This is a brief outline for a clarification of the discussion of this issue.
(1) The Second Amendment to the U.S. Constitution does not establish the right to keep and bear arms. [b]None of the provisions of the Constitution establish any "natural" rights. They recognize such rights, but the repeal of such provisions would not end such rights.[/b] [b]Such rights were considered by many of the Framers as obvious or "self-evident", but they were immersed in the prevailing republican thought of the day, as expressed in the writings of Locke, Montesquieu, Rousseau, Madison, Hamilton, and others, which discussed "natural rights" in some detail.[/b] Others argued that at least some of the rights needed to be made explicit in the Bill of Rights to avoid having future generations with less understanding of republican theory weaken in their defense of those rights. That has turned out to have been a good idea.
(2) The right to keep and bear arms is a natural right of individuals under the theory of democratic government. This was clearly the understanding and intent of the Framers of the U.S. Constitution and was a long-established principle of English common law at the time the Constitution was adopted, which is considered to be a part of constitutional law for purposes of interpreting the written Constitution.
(3) What the Second Amendment also does is recognize the right, power, and duty of able-bodied persons (originally males, but now females also) to organize into militias and defend the state. It effectively recognizes that all citizens have military and police powers, and the "able-bodied" ones -- the militia -- also have military and police duties, whether exercised in an organized manner or individually in a crisis. "Able-bodied" is a term of art established by English common law at the time the Constitution was adopted, and is the only qualification besides citizenship on what constitutes the "militia". While not well defined in modern terms, it is somewhat broader than just able-"bodied": implicit is also "able-minded" and "virtuous". In other words, persons might be excluded who were physically able to bear arms but who were mentally or morally defective. Defense of the "state" includes self-defense and defense of one's family and friends who are, after all, part of the state, but by establishing the defense of the state as primary a basis is laid for requiring a citizen to risk or sacrifice his life in defense of the state and is thus a qualification on the implicit right of self-defense, which is considered to prevail in situations in which self-sacrifice is not called for.
(4) The U.S. Constitution does not adequately define "arms". When it was adopted, "arms" included muzzle-loaded muskets and pistols, swords, knives, bows with arrows, and spears. However, a common- law definition would be "light infantry weapons which can be carried and used, together with ammunition, by a single militiaman, functionally equivalent to those commonly used by infantrymen in land warfare." That certainly includes modern rifles and handguns, full-auto machine guns and shotguns, grenade and grenade launchers, flares, smoke, tear gas, incendiary rounds, and anti-tank weapons, but not heavy artillery, rockets, or bombs, or lethal chemical, biological or nuclear weapons. Somewhere in between we need to draw the line. The standard has to be that "arms" includes weapons which would enable citizens to effectively resist government tyranny, but the precise line will be drawn politically rather than constitutionally. The rule should be that "arms" includes all light infantry weapons that do not cause mass destruction. If we follow the rule that personal rights should be interpreted broadly and governmental powers narrowly, which was the intention of the Framers, instead of the reverse, then "arms" must be interpreted broadly.
(5) The right to keep and bear arms does indeed extend to the states. As do the other rights recognized by other Amendments, and as reinforced by the Fourteenth Amendment. It is not just a restriction on the powers of the central government. On the other hand, the citizens of a state can adopt a constitution that might restrict the exercise of such rights by delegating the power to do so to the state government. However, if the restriction of natural rights is unduly burdensome on those rights, then such a provision would be incompatible with the U.S. Constitution, its guarantee of the rights, and its guarantee that all states have a "republican" form of government - which such restrictions would compromise.