Yet this does not, in my judgment, render the Second Amendment a historical anachronism. It is not consistent with a limited, republican government for law enforcement to take over every aspect of civil defense, broadly understood to include internal dangers (from insurrection to crime) as well as external foes. That would require a massive kind of police/surveillance state. At a certain point, individuals in a republic need to defend themselves and their neighbors. Even though its prefatory clause speaks only about the militia, in spirit the Second Amendment protects this right — just as the First Amendment does not mention the Internet but protects this column.

This analysis also suggests that the Second Amendment is not some willy-nilly license to wield whatever weapon one likes. It establishes an individual right for a public purpose — and it therefore follows that the people, acting through their representatives, can properly set the terms of how that right will be enjoyed. This implies a fairly broad framework for a debate on regulations of armaments — even if, in 1789, weapons technology was so limited that the Founding generation could never anticipate the need for such deliberation.