Now that the grammatical lesson is over...
I would agree that said quoted Rule is not a bad thing. As an operating principle, it can come in very handy to keep in mind. Situational awareness is not only key in responding to a bad situation, but in avoiding them as well.
Now why people like me should remind of that is somewhat of a mystery. Being an Objectivist, the non-iniation of force/fraud/theft doctrine pretty much defines my general philosophy of human interaction. Play nice, and you have absolutely nothing to worry about from me. And no, I don't expect you to have to take my word for it. ;-)
Better read what I wrote again...I spelled it correctly.
My working doctrine remains to this effect: Folks can be sweet and nice around me or they'll get JUNGLE...all the way. My feeling is that if somebody else opens the door to violence, well then, they have no legitimate beef if they get more violence than they bargained for. Sound right?