For most of this blog, I will try to keep it fun and entertaining on some level, but I need to talk about dark, serious subjects every once in a while. In this case, I will discuss necessity.
When you see a situation developing, this means you need to do everything in your power to stop it from getting to such a point where you would find it necessary to fight. Attacking people for no reason or because you think they might do something dangerous in the near future is always unacceptable, as is tolerating such behavior from yourself or others. The first action you must always take is to foresee and prevent. Upon failing one or both of these, you then must resort to neutralizing the attacker. This is almost always the point at which you are attacked.
When someone attacks you, you have to respond with only necessary force. "Necessary force" does not mean that you should weigh every option and find the least damaging viable one in the middle of a conflict; you simply will not have time. This just means that whatever action you take needs to be appropriate for the threat you face. If you see that you can stop a threat, just do it. This will be much less damaging on your body and your psyche than anything you may have to do after hesitating.
Immediately causing a sore neck or shoulder and a few cuts, scrapes, and bruises is better than having to gouge eyes and break bones a moment later.
Immediately gouging eyes and breaking bones is better than having to take a life a moment later.
Taking a life is better than losing your own a moment later.
Which brings us to the deepest, darkest depths to which I will ever delve on this blog where I shatter those childish fighting fantasies of yours and show you that this is not a game.
Killing is as far as you could ever go to defeat an aggressor. It is always an option at every point in a conflict, but it is seldom considered by most. This can be for one or both of two reasons: the person may not have the spiritual fortitude or they may not know how to kill physically.
In films and the media, people are often antagonized for killing out of necessity. Their justification usually comes down to, "I had to" or "I didn't have a choice". Even if it sounds bad on television, the fact that you have to for the survival of yourself or someone you love is the one and only moral justification for taking a life. On the battlefield, a soldier must kill other soldiers because if he doesn't, he and his fellow soldiers may be killed. In the street, if someone threatens your life or attacks you with a knife or a gun and the only viable options you see immediately at first glance are lethal, killing is what you must do. If you find yourself in a more dangerous or complicated conflict, such as an act of terrorism, this would most likely be your only choice.
It is very important that, if you ever have to kill, you do it by choice. Killing is not an easy choice to make and it is usually worse when you either do not get a chance to make it or kill after you've decided otherwise. If you kill someone by accident, it will weigh heavily on your conscience and you will be left without reason, where as if you kill a person on purpose, you know exactly why they had to die. You know they HAD to die because you HAD to kill them; there was no other option.
All of these ideas about moral and psychological reasoning are necessary for the you to understand for your decision making skills and your own mental health, but for every action you take, you should know that there is an equal and opposite legal action that takes place in your state, province, or national government. For this reason, you should study and understand the self defense laws of your local government. It also serves as another powerful reason to foresee and prevent, a protocol that makes almost everything discussed in this post irrelevant in most cases.