On the Aptness of Civilian Possession of Firearms
To discuss firearms I must first establish a foundational principle: the legitimacy of civilian possession of an object hinges on that object's potential to generate significantly more good than harm. Pens are, with little doubt, apt for civilian to own; they pose little danger, and a world without pens would be a troublesome world to live in. Chairs are also apt for citizens to own for the same reason as those of pens. Their inherent harmlessness and ability to generate good justifies their widespread possession.
Conversely, the immense potential for destruction of objects like nuclear warheads and missiles renders them unsuitable for civilian possession despite the miniscule possibility for benevolent actors wielding them for good (e.g. using warheads to kill terrorists).
The objects discussed about provide a framework for determining how justified it is for some object to be in civilian possession: an object's potential to generate significantly more good than harm deems it apt for civilian possession, while the converse deems it otherwise. To visualize this framework, I will introduce a scale to denote the aptness for the civilian possession of certain objects:
Should an object be placed to the right, then civilian possession of that object is justified; should an object be placed to the left, then civilian possession of that object is unjustified. The matter of whether an object should be available in civilian possession - including firearms - boils down to its placement on this scale. However, firearms are particularly tricky; they can protect and harm, both to a great extent, which makes their placement on the scale difficult.
Perhaps another object that is similar to firearms in this regard may be considered: knives. Knives generate good by making tasks like cooking easier, but also generate harm if they are used to, for example, physically harm. I recognize that knives are generally considered apt for civilian possession and thus must clarify that I do not advocate a projection of knives' civilian possession onto firearms, but I do wish to raise a point: any object, however small, has the potential to generate harm; conversely, any object also has the potential to generate good, and whether if good or bad would be generated from the object depend on its actor; e.g. a nuclear warhead given to a righteous person would be less worrisome than a pen given to a delinquent.
Thus, I do not advocate for an overly-thorough consideration of the potential for objects, including firearms, to generate good or bad, but a more rigorous consideration of whom we allow to possess these objects.