Stopping a rape certainly is an aggressive act...
No, it is a
defensive act, specifically, third-party defense. Aggression is
initiating the use of force. If I stop a rape, I am not initiating the use of force, I'm stopping it.
If I interrupt a screamer and her boyfriend, then I am initiating the use of force, because there was no force being used in the first place. In that situation, I am the aggressor, and would apologize and leave, very embarrassed.
And yet, you cannot see the error in your logic, even now.
And you would not apologize and leave. You would, at a minimum, have to face restitution for whatever harm you caused; even in your ideal ancap world. And that's the best case scenario. If your intentions were misinterpreted by the lovers, you'd as likely be shot;
and under such case their interpretations of your intent would be the material one.Beating a kid is decidedly the use of force, and intervening is not aggression, it's defense - stopping the use of force, by force if necessary.
You insist on using a biased strawman argument, but whatever. Again, defense is use of force. Whether or not it is defensive in nature, in third party defensive situtations, is not dependent upon your interpretaion of the situation, but your presumed victim's. Again, if you are wrong, you are the aggressor. Everyting flows from the interpretaion
after the fact, but in the heat of the moment there can be many interpretions.
Tell me, if you saw someone kicking a defenseless man in the street, would you do anything about it, or let it be? If you would do something, what?
Depends on too many factors that you have left unmentioned. As I have already pointed out; would be good samaritains have gone to prison for miss-interpreting a situation. One in particular that comes to mind, some years ago a man entered a bar that he regularly frequents, and immediately encounters a group of men beating upon a single man. He assumes that the group of men were the aggressors, and pulls out a 38 special revolver. He finds out, much later, that the group of men were off-duty policemen out having a good time, and that the man on the ground was a neo-nazi skinhead who, after discovering that a group of cops were in the bar, proceeds to sling slurs at the cops, calling them "pigs", and throwing small objects from the bar at them in a drunken state. Granted, that guy went to prison for pulling a weapon on police, not for missinterpreting an encounter or harming anyone, and he shouldn't be there; but there he is. I would ceratinly take much more care to understand such a situation, if for no other reason than the protection of people that I don't know is less of an obligation upon myself than protecting
myself from the aggressions of any party to a conflict. I am not obligated, by the NAP or otherwise, to intervene
at all.