Many arguments against allowing private gun ownership or gun carrying strike me as quite plausible; I think they're mistaken, but they make sense. The arguments claim that banning guns would provide more benefits, especially in saving people's lives, than the costs that such a ban would impose (frustrated self-defense, decreased deterrence, and other things). I think that this argument is empirically unlikely, and morally troublesome. But it makes sense on its own terms.
Occasionally, though, I run across a different phenomenon — both as to guns and as to other things — that I think of as "self-defense-blindness": a complete failure to even consider self-defense as one of the functions of a gun or other weapon. Either the speaker doesn't even think of self-defense, or at least he assumes that the listener can be persuaded not to think of self-defense.
We see this, for instance, in claims that some guns should be banned because they lack a "sporting purpose," without considering a possible self-defense purpose. We also see this in statements that guns are good only for killing. Even if one includes threatening to kill alongside killing (and ignores target-shooting), talking about "killing" in condemning guns without distinguishing criminal killings/threats from self-defense killings/threats strikes me as self-defense-blindness.
But in doing research for my nondeadly weapons article, I saw the same for non-firearms devices as well. Consider Tear Gas — Pencil Gun — Dangerous Weapon, 26 Opinions of the Connecticut Attorney General 207 (1950). The question was whether "tear gas pencil gun[s]" (described basically as individualized irritant spray weapons) should be treated as "dangerous or deadly weapon[s]" for purposes of the Connecticut statute banning the carrying of such weapons without a permit. The A.G. said yes, and that's a plausible bottom-line, if the question is just whether the device is dangerous. But consider the A.G.'s rationale:
It is obvious that the function of this so-called pencil gun is to injure and to disable an individual and it is inconceivable that this instrument would be used or has any other function than to disable temporarily or permanently. It may well be that in the hands of proper authority, such as a police official, the temporary disabling of an individual or individuals may ultimately serve a useful function. However, in the hands of an individual without any such authority, there is no question but that the pencil gun could only be calculate [to] injure.
It is our opinion, therefore, that the so-called tear gas pencil gun is a dangerous and deadly weapon within the provisions of [the statute].
So the only "useful function" for a tear gas pencil gun is when police officers use it to temporarily disable people. The possibility that a citizen who wants to defend himself (or herself) might "useful[ly]" do so with a tear gas pencil gun is simply omitted. Nor is the A.G. simply commenting on the physical reality that the tear gas pencil gun can be dangerous regardless of whether used for good or ill; he's making a normative judgment that the device is "useful" when used by the police, but not even discussing whether people might find it equally "useful" for self-defense.
I saw the same in a 1976 Pennsylvania Attorney General opinion on Tasers, 75 Pa. D. & C. 2d 597, which opines on whether tasers are covered under the Pennsylvania ban on possessing "offensive weapon[s]." The law defined offensive weapons as any "implement for the infliction of serious bodily injury which serves no common lawful purpose." The A.G. treated incapacitation by Taser as a form of "serious bodily injury," an odd reading but one I won't quarrel with here. But that still left the question whether a Taser "serves no common lawful purpose." Here's the A.G.'s reasoning:
(1) "Common lawful purpose" should be neither "so strictly construed that no item would be prohibited by the phrase" nor "so loosely construed that all items would be prohibited," but should "be given a reasonable common sense interpretation."
(2) Under this "common sense" approach, "The Taser, like a 30-inch knife, metal knuckles, and a sawed off shotgun [devices that had been found to 'serve no common lawful purpose' under past precedents], and unlike a butter knife, scissors, or a pack of razor blades, is capable of inflicting serious bodily injury and serves no common lawful purposes," and is thus banned.
Nowhere is there any mention of the possibility that self-defense might be a "common lawful purpose" for Taser ownership. The A.G. doesn't even mention self-defense as a possible purpose, or discuss why he thinks criminal purposes would be more common than self-defense purposes. Nor does he adopt the unsound but at least not self-defense-blind view that self-defense doesn't matter because the uncommonness of Tasers means that none of their purposes, lawful or otherwise, are "common." Self-defense is just ignored.
Likewise, consider People v. Smelter, 437 N.W.2d 341 (Mich. Ct. App. 1989), the only case that considers whether stun guns are protected under a state right-to-bear-arms provision. Here's the entirety of the reasoning that says they aren't protected:
Third, defendant claims that the statute prohibiting the possession of stun guns impermissibly infringes on defendant's right to keep and bear arms for his own defense. We disagree. Const. 1963, art. 1, § 6 provides: “Every person has a right to keep and bear arms for the defense of himself and the state.”
The right to regulate weapons extends not only to the establishment of conditions under which weapons may be possessed, but allows the state to prohibit weapons whose customary employment by individuals is to violate the law. [People v. Brown, 235 N.W. 256 (Mich. 1931) (upholding a ban on carrying blackjacks).] The device seized from defendant was capable of generating 50,000 volts. Testimony in the lower court established that such weapons can not only temporarily incapacitate someone but can result in temporary paralysis. Our Supreme Court in Brown explained that the power to regulate is subject to the limitation that its exercise be reasonable. We conclude that the Legislature’s prohibition of stun guns is reasonable and constitutional.
Let's say that the right to bear arms really shouldn't extend to weapons "whose customary employment by individuals is to violate the law." The trouble is that the court doesn't offer any evidence that stun guns are customarily used for crime rather than self-defense. (None of the briefs in the case offered any such evidence, either.)
The court's argument simply points out that the weapon is potentially dangerous — well, of course it is, since all devices and techniques for violence, even in entirely lawful self-defense, are dangerous. Paralyzing an attacker in lawful self-defense can be entirely permissible. But the court's analysis was self-defense-blind: The possibility of self-defense didn't even come up.
And all these examples aren't about guns. They can't just be described as the direct effect of hostility to guns. Nor can they be defended on the grounds that they implicitly borrow from the standard critique of gun ownership. Rather, they seem to be part of a broader blindness to self-defense, and an unthinking assumption that the "useful function," the "common lawful purpose," and the "customary employment" of weapons simply doesn't include lawful self-defense.
All the states of the union legally allow self-defense. They even allow deadly self-defense when necessary to repel a threat of death, serious injury, rape, kidnapping, or in many states robbery (or even burglary). But despite this, the arguments I quoted above (and many like them) simply ignore self-defense altogether. The arguer is self-defense-blind, or he wants his listeners to be.