Walter Dellinger, counsel for the District of Columbia, started by arguing that when Madison used the phrase "bear arms," he meant exactly "render military service" (pages 3-4). His argument is from Madison's original draft of what became the second amendment. The draft reads:
"The right of the people to keep and bear arms shall not be infringed, a well armed and well regulated militia being the best security of a free country, but no person religiously scrupulous of bearing arms shall be compelled to render military service in person."
Not addressed by Dellinger, or by the linguists' brief, is the role of "keep" in "keep and bear arms." If "bear arms" is just a way of saying "carry weapons" (or "carry arms," if military arms are to be distinguished from non-military weapons), then coordinating "keep" and "bear" makes sense: the amendment says that there's a right to keep the arms and to carry them.
But if "bear arms" is an idiom meaning "render military service," then an explanation of "keep" needs to be more complicated. There could be an idiom "keep and bear arms," which to my knowledge nobody has argued. Or there could be an idiom "keep arms" which is coordinated with an idiom "bear arms." But nobody seems to have claimed that either, and who says you can coordinate idioms like that? Or it could be that "keep" is not part of the idiom, but nevertheless can take "arms," part of the idiom, as an object.
General Paul Clement, supporting DC as amicus curiae, picks up on the "keep" problem:
And, obviously, the term "keep" is a word that I think is something of an embarrassment for an effort to try to imbue every term in the operative text with an exclusively military connotation because that is not one that really has an exclusive military connotation. (p. 29)A discussion on "keep," "bear" and "arms" follows on pages 34-38.
Related to this is another linguistic debate, concerning whether the right to keep and bear arms is two separate rights - the right to keep arms and the right to bear arms - or a single right, presumably the right to both keep and bear arms. It might seem implausible for the Constitution to be defining a single right, which could be taken to mean (though it doesn't have to mean) that the federal government could ban the keeping of arms, and could ban the bearing of arms, but it could not ban doing both of those things.
But Justice Stevens has a good linguistic argument for this interpretation. He points out (p. 38) that "[i]t's one right to keep and bear, not two rights, to keep and to bear." In other words, the fact that there's no "to" in front of "bear" makes the text support a single right rather than two. It's analogous to the way the following sentences differ.
The study of law and economics is silly.Although both sentences may be true, they mean different things. The first is talking about a single discipline, while the latter is talking about two separate ones.
The study of law and of economics is silly.