Well, the best defense is a good offense so if some one is going to be aggressive against you, you need to be aggressive first! Just kidding! I don't think there is anything wrong with the non-aggression principle. Like I said, it is actually what I practice. I do however envision a future without even the need for self defense. This is an ideal. Not only is it possible, it is inevitable. I don't expect you to believe this, but it will happen. It is what we are evolving towards.