P since Q. And guns.

The Second Amendment

A well regulated militia being necessary to the security of a free state, the right of the people to keep and bear arms shall not be infringed.

A hypothetical imperative does not become assertoric merely because someone alleges the antecedent.

That is to say, the consequent is not detached merely on that account.

Not even if the one alleging is the one who uttered the imperative in the first place.

True enough, if Mom says “Come inside if the grass is wet” she is apt to be cross if she comes to believe, though falsely, that the grass is wet, and you have stayed outside.

She will think, in that case, that you are a wicked child.

But even so, though you linger in dry fields to her annoyance you do not thereby disobey.

And the case is not different if she believes the grass is wet when she says “Come inside if the grass is wet.”

Not even if she says it’s wet, right then, within your hearing.

But the case is very different if she says “The grass is wet. Come inside.”

Then, the command is unconditional, though accompanied by an assertion of what she takes to be a reason for issuing it that happens to be false.

Then, indeed, you are a wicked child if you remain outside in the bone-dry grass.

So how are you to understand her when she says, to your confusion, “Since the grass it wet, come inside”?

Is that the same as “The grass is wet; come inside”?

Or as “The grass is wet; if the grass is wet come inside”?

As a purely practical matter you should probably go inside, yes.

But suppose Mom, as soon as she spoke, left on vacation, leaving your elder sister to enforce her will, though she understands perfectly well that the grass is not wet?

Is she to take the imperative content of Mom’s utterance to be assertoric or merely hypothetical?

Is she to think you must come inside, and she must make you come inside, regardless of whether the grass is wet, all because Mom absurdly thought it was?

Or that, since the grass is dry, you need not come inside and she need not try to make you?