I often hear people say that fighting should only be used as a last resort or that they want to learn martial arts for self-defence. That sounds pretty good in theory, but life is a little more complicated than that. I wish things were so simple that you could just walk around doing your thing and then only resort to violence when ruffians rear their ugly heads and start trouble (always after they strike first, of course).
Unfortunately, violence is a complicated and touchy issue. There really is no such thing as self-defense. If you can handle someone without hurting them, they really were never much of a threat. I myself am pretty good with self-defense against 5 year-olds and old ladies. The real question is "when is violence warranted?" This is a moral question for most of us, but for many, it's more an issue of survival. People struggling to survive might find the whole concept of morality when it comes to fighting a bit silly. If you are in a situation, area or place where no one is protecting you, you may have little choice about when you have to fight.
On the question of "when is violence justified?" which I consider from the comfort of a middle class background and residence in a developed country, I think there are three basic situations when you should perhaps fight or employ violence.
1. Protecting yourself, friends or family from physical harm.
2. For long-term status and well-being: This is complicated so I will give a few examples. If there is someone that you live with or near that you often see that uses physicality or threats or implied threats, you need to be willing to have a physical confrontation in order to keep your status. This is usually more important for boys and men than women but can apply for them as well. There are almost always other ways to get what you want out of situation rather than fight, but you may not know how to do them. They are easier to learn if you are willing to fight. A lot in the rough and tumble world of status depends on willingness to fight rather than the ability to win.
Sometimes you see a little brother who is picked on by a big brother. When the little brother fights with everything he has, the big brother will often relent. In the adult world, there may be a big guy that uses implied threat to punk people out (pushing them, grabbing their head), strong objection and willingness to fight, can often put an end to this. When you use fighting in this way, you have to ask yourself if the loss in status, annoyance or humiliation is worth getting hurt badly and make a decision. One principle to remember in these kinds of conflicts is that it is easier to fight back or resist the first time someone messes with you. If you let someone hit you or grab you or disrespect you for a year and then object, expect strong resistance. The first time someone messes with you, they are testing what you will put up with and usually will back off at the first sign of opposition. After you have allowed the behavior for a while, they have already put you at a certain status, so when you resist you are upsetting the status quo in their minds.
3. Fighting over resources: Sometimes you have to fight to get or keep, food, family and/or space. This one is kind of a cop out on my part, because it encompasses the full gamut of war, murder and most kinds of "evil". Who knows what is absolutely necessary to survive? It kind of depends on each unique situation. Any animal understands this, but humans don't really have to think about it until their backs are against the wall. I suppose in extreme enough circumstances, almost any violence could be justified by the need to survive. It's complicated.
And that is really the point of this entry. When is violence justified? Its hard to say, but I don't think it helps to pretend that violence is not a fundamental part of our reality. It is not something that is avoided by good people and performed by evil people. It's easy to think of it as something done by base individuals, but in my experience, if someone thinks that violence is a horrible thing that should always be avoided they are being protected by someone else who will have to face the question of violence whether it be a husband, policeman or soldier.
Some people think violence is only justified when protecting yourself, which i find a little naive. On the other hand, I can't stand when people use flimsy reasoning to justify hurting someone that is not a real threat to them. Many people will attack someone for "insulting" their wife or girlfriend, but it seems to me that they only do it when they are sure they can "win". Or other times, there is an obnoxious but harmless drunk. Many people will line up at the chance to harm the guy because they get the chance to hurt someone and be "in the right". Harming someone who is not a direct or indirect threat is simply giving in to our most base instincts and is indefensible in my opinion. Doing it to punish those who are seen as being "wrong" according to some ever-changing arbitrary standard is perhaps the worst form of unjustified violence. Harming people who are "in the wrong" when you have the power is a human instinct that helps give rise to societies that begin to eat themselves as occurred in Nazi Germany, Cambodia, China and many other countries.
I guess what I am saying is that it is quite simple, violence against actual threats is often justified. Violence against non-threats is usually not justifiable. The hardest part may be determining what is a threat and what isn't.